Ultimativer Leitfaden zur Herstellung von Polyurethan-Rüstungen

The Ultimate Guide To How Polyurethane Armor Is Made

Modern LARP armor has changed significantly over the past decade. While steel and leather equipment still remain popular choices in many communities, more workshops and players are exploring alternative materials that offer a different balance between realism, comfort, durability, and mobility.

One material that has gained increasing attention is polyurethane (PU) resin. This production method is now widely used for lightweight armor designed for long-duration events, festivals, NPC equipment, stage performances, cosplay, and immersive roleplay experiences.

At LARPSHOPKEEPER, polyurethane armor is produced through digital sculpting, traditional hand-finishing, silicone mold-making, and layered casting techniques. The result is armor that maintains a realistic fantasy appearance while staying practical for active use during LARP events.

This guide explains the full workflow behind modern polyurethane LARP armor production, from the first character idea to the final painted armor ready for shipping.

What is Polyurethane Resin
Ultimativer Leitfaden zur Herstellung von Polyurethan-Rüstungen

Since this guide focuses on modern polyurethane LARP armor, it makes sense to begin with the material itself. Understanding what polyurethane resin is and why it is used helps explain many of the manufacturing decisions discussed throughout the rest of this guide.

Polyurethane resin is a versatile casting material widely used in prop making, special effects, industrial prototyping, museum displays, and many other industries that require lightweight yet durable parts. Depending on its formulation, polyurethane can be rigid, semi-flexible, impact-resistant, or specifically engineered for different manufacturing applications. This versatility is one of the reasons it has become so popular among professional prop makers and costume workshops.

For LARP armor, however, polyurethane resin is rarely used on its own. Although it captures fine details exceptionally well, large cast parts made solely of resin may become too brittle or prone to cracking under repeated stress. This is why many professional workshops reinforce polyurethane armor with fiberglass during casting.

Fiberglass serves as internal structural reinforcement, much like the reinforcing bars in reinforced concrete. Rather than simply making the armor thicker, layers of fiberglass cloth help distribute stress throughout the entire structure, significantly improving rigidity, durability, and long-term resistance to repeated use. At the same time, this reinforcement allows armor pieces to remain relatively lightweight without sacrificing their overall strength.

The combination of polyurethane resin and fiberglass reinforcement has proven to be one of the most effective solutions for creating modern LARP armor. It allows manufacturers to produce highly detailed pieces that are durable enough for repeated use at events while remaining comfortable to wear throughout long weekends of roleplay, walking, and combat.

Compared to foam armor, rigid polyurethane preserves much sharper details, cleaner edges, and more defined surface textures. Compared to traditional steel armor, it offers a significant weight reduction while requiring considerably less maintenance. Rather than replacing traditional materials entirely, polyurethane has established itself as another practical option for players who value a balance between realism, durability, and comfort.

As you'll see throughout this guide, the material itself is only one part of the equation. The quality of the final armor depends just as much on proper mold-making, fiberglass reinforcement, careful casting, finishing, and painting as it does on the resin used.

Understanding the material itself is only the first step. The next question is why modern workshops choose different materials for different projects. Before looking at the production process itself, it's worth understanding what makes each material suitable for a particular job.

Choosing Right Material For the Project
Polyurethan- vs. Stahl- und Leder-LARP-Rüstungen

Now that we've covered the material itself, it's worth taking a step back and understanding why polyurethane became such a popular choice for modern LARP armor in the first place.

For centuries, armor was primarily crafted from steel and leather. Both materials have earned their place throughout history and remain widely used today in historical reenactment, stage productions, fantasy costumes, and many other creative fields. They remain excellent choices when their unique characteristics match the intended purpose.

As LARP continued to evolve, however, so did the expectations placed on armor. Modern events often last several days and involve long hours of walking, roleplaying, combat, and travel between locations. Players also began creating increasingly detailed fantasy characters that required armor designs far beyond traditional historical styles. These changing demands encouraged workshops to explore alternative materials that balance visual realism, comfort, durability, and practical usability.

Modern composite materials, including fiberglass-reinforced polyurethane, became one of those solutions. Rather than replacing traditional armor materials, they introduced a different manufacturing approach focused on creating lightweight equipment that could capture intricate sculpted details while remaining suitable for repeated use during LARP events.

Steel Armor

Steel remains the benchmark for historical authenticity. Its appearance, weight, and craftsmanship make it the preferred material for historical reenactment, museum reproductions, and full-contact armored combat. Few materials can replicate the feeling of wearing real forged steel.

For LARP, however, steel also adds weight, requires regular maintenance, and imposes greater physical demands during long events. Depending on the style of the game and personal preference, these factors may or may not be important considerations.

Leather Armor

Leather has been used in armor for centuries and remains popular for many fantasy character archetypes, particularly rangers, rogues, hunters, and lightly armored adventurers. It offers excellent flexibility and a distinctive handcrafted appearance that suits many settings.

Producing highly detailed fantasy armor from leather, however, often requires significant manual craftsmanship. Complex decorative elements, deep engravings, and perfectly symmetrical designs can be more challenging to reproduce consistently, especially when multiple matching armor sets are needed.

Modern Polyurethane Armor

Modern polyurethane armor approaches the same challenge from a different direction. Instead of prioritizing historical authenticity above everything else, it focuses on creating equipment that is practical for modern fantasy events while preserving a high level of visual detail.

When reinforced with fiberglass, polyurethane becomes a durable composite material capable of reproducing complex sculpted designs with remarkable consistency. This manufacturing approach allows workshops to create individual custom LARP armor commissions, complete armor sets, and multiple matching pieces while maintaining the same overall quality and level of detail.

Each of these materials has its own strengths, and none should be viewed as a universal replacement for another. Understanding their different characteristics provides useful context before moving into the manufacturing process itself. In the following sections, we'll explore how modern polyurethane armor is designed, reinforced, cast, assembled, and finished, from the initial concept through to the completed armor piece.

Pros and Cons
Vor- und Nachteile von PU-LARP-Rüstungen

We now have a better understanding of why polyurethane became one of the leading materials for modern armor. Like any material, however, it is not perfect. Every manufacturing method involves compromises, and understanding both the advantages and limitations of polyurethane armor helps set realistic expectations before exploring the production process itself.

Every armor material comes with its own advantages and limitations, and polyurethane is no exception. The "best" choice always depends on the intended purpose of the armor, the type of event, personal preferences, and the desired balance between historical authenticity, comfort, durability, and visual appearance.

Over the past decade, PU armor has become increasingly popular because it successfully addresses many of the practical challenges encountered during modern LARP events. At the same time, there are situations where steel, leather, or other materials may still be the preferred solution. Understanding these trade-offs provides a more complete picture before diving into the manufacturing process itself.

Advantages

Every material used for armor production has its own strengths, and polyurethane is no exception. Its growing popularity within the fantasy industry is largely the result of balancing several practical characteristics rather than excelling in just one area. Instead of focusing solely on historical authenticity, modern composite manufacturing aims to combine detailed aesthetics, structural durability, comfort, and efficient production into a single workflow.

Lightweight Construction

One of the most noticeable characteristics of polyurethane is its relatively low weight. When combined with fiberglass reinforcement, large cast components can remain significantly lighter than comparable steel components while still providing the rigidity required for repeated-event use. For productions involving large costumes or complete armor sets, reducing overall weight often improves both comfort and mobility without compromising the visual appearance of the finished piece.

Exceptional Detail Reproduction

Polyurethane resin performs exceptionally well when reproducing fine sculpted details captured by silicone molds. Sharp edges, engraved ornaments, layered surfaces, decorative textures, and weathered effects can all be transferred with remarkable accuracy. This allows artists and sculptors to preserve the original design across multiple castings while maintaining consistent detail.

Composite Reinforcement

Contrary to what many people imagine, the finished casting usually relies on more than just resin. Fiberglass reinforcement transforms individual castings into composite structures that are considerably stronger than solid resin by itself. Proper reinforcement distributes stress more evenly throughout the part, increasing durability while avoiding unnecessary material thickness.

Repeatable Manufacturing

One of the greatest advantages of mold-based production is consistency. Once a master model and silicone mold have been completed, identical components can be reproduced multiple times with the same dimensions and surface quality. This makes the manufacturing process particularly suitable for complete armor sets, matching equipment, replacement parts, and larger production runs.

Low Maintenance

Unlike ferrous metals, cured polyurethane does not rust or require corrosion protection. Routine care usually consists of basic cleaning and proper storage, making finished equipment easier to maintain after outdoor events or transportation.

Limitations

Although polyurethane resin offers many practical advantages, it should not be viewed as a universal replacement for every traditional material. Like any manufacturing solution, it also has limitations that should be understood before choosing it for a particular project on your table.

Different Purpose Than Steel

Polyurethane and steel are designed to solve different problems. While steel remains unmatched for historical authenticity and armored combat, modern composite materials prioritize weight reduction while maintaining visual realism. Comparing the two as direct competitors often overlooks the fact that they were developed for different applications.

Complex Manufacturing Process

Despite the lightweight nature of the finished pieces that we usually make, the production workflow itself is far from simple. Creating a single component typically involves concept design, digital sculpting, prototype printing, mold making, casting, reinforcement, trimming, painting, leatherwork (for straps or other attachments), and final assembly. Every stage influences the quality of the finished result, making skilled craftsmanship just as important as the materials themselves.

Time-Intensive Preparation

The greatest investment usually occurs before the first casting is ever produced. Designing a master model, printing prototypes, creating silicone molds, and building rigid support shells require considerable time, precision, skills, and, of course, money. Once these stages are complete, however, the same tooling can be used to manufacture multiple matching components with consistent quality. That's basically how our workshop operates.

Material-Specific Applications

Composite materials perform exceptionally well in the environments for which they were designed, but they are not intended to replace every traditional armor system. Projects involving historical reconstruction or full-contact steel combat naturally demand different engineering solutions and different materials. Selecting the appropriate material, therefore, depends on the intended application rather than searching for a single universal answer.
Warum das Gewicht der wichtigste Faktor bei einer Rüstung ist

Why Lightweight Armor Matters in LARP

One of the biggest differences between trying on a costume kit for a few minutes and participating in a real LARP game is the amount of time you actually spend wearing your equipment. New players often imagine combat as the most physically demanding part of the experience, but in reality, much of the day is spent walking between locations, standing through roleplay scenes, interacting with other participants, carrying personal belongings, and simply living in character.

Large festivals like DrachenFest or Conquest of Mythodea can easily last several days, with participants remaining in costume for ten or more hours each day. During that time, even relatively small differences in additional weight on your shoulders and back become increasingly noticeable. Fatigue builds gradually; your movement becomes less efficient; and carrying unnecessary weight eventually affects both physical comfort and overall immersion, leading you to drop off your kit at the camp and dress into something comfy.

This changing style of gameplay is one of the reasons modern LARP has gradually shifted toward lighter construction methods. Rather than focusing only on historical authenticity, many workshops now consider long-term wearability, ease of movement, transportation, and practical comfort as equally important design goals.

Ultimately, reducing weight is not simply about making equipment easier to carry. It allows players to stay active, comfortable, and immersed throughout an entire LARP game. Once comfort stopped being viewed as a luxury and became part of the overall experience, workshops also had to rethink the way they approached design and manufacturing. That shift has played an important role in shaping modern costuming equipment.

Why Modern LARP is Changing
Warum sich modernes LARP aufgrund der Hitze auf den Spielfeldern verändert

If you've ever walked through a large LARP festival, you've probably noticed one thing almost immediately: every year, the level of visual detail seems to become more impressive. Camps feel more immersive, costumes are more elaborate, props are more believable, and characters often look as though they have stepped straight out of a fantasy novel, video game, or cinematic production.

For many players, creating a memorable character has become just as important as participating in combat. Equipment is no longer viewed simply as something worn for protection during battles. It has become part of the storytelling itself. The silhouette of a character, carefully sculpted details, weathering effects, heraldry, symbols, and overall visual consistency all help create a stronger sense of immersion for both the player and everyone around them.

In our opinion, professional event photography and social media have also contributed to this shift. Long before attending their first festival, many newcomers spend hours looking through photographs, videos, and event galleries filled with incredibly creative characters. Those images inspire people to develop original concepts of their own, raising expectations not only for costume design but also for craftsmanship and overall presentation.

Naturally, these expectations have influenced the way many workshops approach manufacturing. Creating equipment today is no longer only about producing functional costume pieces. It is equally about transforming increasingly ambitious artistic ideas into physical objects while maintaining consistency, comfort, and practical usability.

The production methods described throughout this guide directly reflect that evolution. Digital sculpting, high-resolution 3D printing, silicone mold-making, composite casting, and traditional hand finishing all work together to address different manufacturing challenges for workshops. Rather than replacing craftsmanship and people behind those skills, these technologies have expanded what makers can create, allowing increasingly complex fantasy concepts to become reality.

From Concept To Finished Piece

Now that we've looked at the materials, manufacturing principles, and the reasons modern production methods have become so widely adopted, it's time to move from theory to practice.

In the following chapters of our guide, we will walk through the complete props production pipeline used in our workshop - from the very first character sketch to the finished, painted piece ready for shipping. Every upcoming stage builds on the previous one, and understanding this workflow helps explain why creating high-quality equipment involves far more than simply pouring resin into a mold. So make yourself comfortable and let’s begin!

Step 1. Character Concept And Basic Idea

Every project starts with an idea.

Sometimes that idea already has a clear direction. A client may come to us with existing artwork, references from games, films, books, or previous LARP characters. In other cases, the project begins with nothing more than a short conversation and a few rough thoughts about the type of character they would like to play.

At this stage, our team's goal is not to create finished artwork or to consider manufacturing techniques. Instead, all our crafters, digital sculptors, and designers focus on understanding the character itself. Who is this person? What role do they play on the battlefield? Should the equipment look elegant, intimidating, ceremonial, battle-worn, or practical? These early decisions form the foundation for every subsequent production stage at our workshop.

One of the first things we discuss as a production team is whether the original idea can realistically be made into a wearable piece of equipment. Fantasy illustrations often exaggerate proportions to create dramatic visual effects. Massive shoulder pieces, oversized horns, extremely narrow waists, or unusually small heads may look spectacular in concept art, but not every artistic idea can be translated directly into something comfortable, safe, and practical for real use.

Our role at LARPSHOPKEEPER is to find the right balance between the original artistic vision and the realities of physical production. Whenever possible, we preserve the character's identity while making adjustments that improve wearability, movement, visibility, transportation, or long-term durability. In many cases, these changes are barely noticeable visually, but they make a significant difference once the finished equipment is actually worn during an event.

Safety also becomes part of the hot discussion from the very beginning. Many big LARP events have their own equipment guidelines, and even when they do not, we generally recommend avoiding unnecessarily sharp spikes, rigid protruding elements, or decorative features that could pose risks during combat or roleplay. In many situations, the same visual effect can be achieved using different construction methods or alternative materials without altering the design's overall appearance.

When developing original products for our own collection, we also think beyond a single character. We consider whether the overall concept will appeal to different players, how well it fits within existing product lines, and whether it can become part of a broader collection in the future.

Custom projects introduce another important question. Sometimes the equipment is intended for a single character, while in other cases, entire guilds, NPC teams, or player groups may eventually want matching equipment. Understanding these plans early helps us make better design decisions before the project moves into the visual development stage.

Once the overall concept has been agreed upon, the project is ready to move from ideas and discussions into the first visual representation of the character.

Step 2. Creating 2D Concept Art
How It's Made - Creating 2D concept

Once the overall direction of the project has been established, the next step is creating concept art. This is the stage where ideas begin to take shape visually, allowing both the client and the workshop to see how the future project may look before any time is invested in 3D sculpting or manufacturing.

Although 2D concept art is often viewed simply as an illustration, it serves a much more practical purpose within the production pipeline of our “creative garage”. It allows us to test different design ideas, experiment with proportions, adjust individual armor elements, and evaluate the character's overall visual balance. Making these decisions on paper or digitally is significantly faster and less expensive than modifying a completed 3D model later in the project.

During this stage, we often explore several different directions before settling on the final design. Small changes to shoulder size, helmet shape, decorative ornaments, armor layering, or silhouette can dramatically affect how the finished character looks. Even subtle adjustments made at this point may save many hours of additional work during the following stages of production.

Complete concept art (sometimes sketches) usually includes front and back views of the character, while more complex projects may also require side views or detailed drawings of individual elements. Close-up illustrations, material references, color palettes, heraldry, and decorative motifs help establish a clear visual language before digital sculpting begins. The more information available at this stage, the fewer assumptions our sculptors will need to make.

Besides, another very important part of concept development is communication with the client. Rarely is the first version the final one. Most projects go through several rounds of feedback, allowing proportions, details, and overall styling to be refined before approval. This collaborative approach helps ensure that both sides share the same expectations before the project moves into the much more time-consuming stages of digital production.

In our experience, a well-developed concept is one of the best investments in the entire workflow. It reduces uncertainty, prevents unnecessary revisions, and provides a clear visual reference that everyone involved in the project can follow throughout the rest of the manufacturing process.

Once the concept has been approved, it becomes the blueprint for the next stage: creating a detailed three-dimensional model that will eventually be transformed into a physical object.

Step 3. Sculpting Pipeline
How It's Made - 3D sculpting

Once the concept artwork has been approved, the project moves into the digital sculpting stage. This is where a two-dimensional illustration begins transforming into a complete three-dimensional model that can eventually become a physical object.

Unlike concept art, which focuses primarily on visual direction, 3D sculpting must also consider how every part will exist in the real world. Every surface, edge, decorative element, and armor plate becomes actual geometry rather than a simple illustration. At this stage, artists define the exact proportions, shapes, and construction of each component while preserving the overall style established during concept development.

Digital sculpting provides an extraordinary level of precision that would be difficult to achieve using traditional methods alone (which we still use sometimes). Symmetry can be controlled accurately, layered armor plates can be built with realistic depth, and fine decorative details such as engravings, ornamental elements, and surface textures can all be refined before a single physical prototype is produced. This gives artists the freedom to explore highly detailed fantasy designs while maintaining consistency across the entire project.

As the model develops, future equipment is gradually broken down into individual components that will later become separate physical parts. This involves far more than simply cutting the model into pieces. Every component must already be designed with manufacturing in mind. Attachment points, overlapping sections, hidden fastening systems, wall thickness, and areas intended for future reinforcement all need to be considered before production begins.

Also, we highly recommend separating each armor part into its own project and keeping track of the latest revisions in your computer folders. And don’t forget to save files frequently and make backups!

Large projects can quickly become surprisingly complex, especially with the “non-stop need” to add even more details. A complete armor set may consist of dozens of individual parts (sometimes mirrored), each requiring careful planning to ensure everything fits together correctly after casting and assembly. Although the finished equipment appears as a single design, it is actually built from many separate components that must function as one cohesive system.

The images below show several stages of the development of our Flower Knight project. Like many large-scale designs, the model evolved gradually as new ideas, construction solutions, and practical considerations were introduced throughout the sculpting process. We will take a closer look at that iterative workflow in the following chapters.

The result of this stage is a complete digital model that accurately represents the future project and is ready to move into physical prototyping.

Step 4. Test With FDM Printing
How It's Made - FDM Test 3D print

Once the initial digital model is complete, the next step is to produce physical prototypes using FDM 3D printers. Although these prototypes will never become part of the finished equipment, they play an essential role in evaluating the design before moving on to high-resolution resin printing and mold production.

One of the biggest advantages of physical prototypes is that they immediately reveal issues that are difficult to notice on a computer screen. Even a perfectly modeled digital file may feel completely different once it is held in your hands or worn on the body. Test prints allow us to evaluate overall proportions, ergonomics, assembly, movement, visibility, and the interaction of individual parts before investing time and materials in subsequent production stages.

Our workshop operates a large FDM printing farm built around modern printers from Bambu Lab, Prusa, and Elegoo. Since multiple custom projects are often developed simultaneously, having multiple printers allows us to produce prototype parts in parallel rather than waiting for one machine to finish before starting the next. This significantly reduces development time, especially when working on complete armor sets consisting of dozens of individual components.

Large armor pieces frequently exceed the build volume of a single printer. In these situations, the digital model is divided into smaller sections that can be printed separately and assembled afterward. Printing several components simultaneously on different machines allows us to evaluate an entire section of the project much sooner than would otherwise be possible.

That said, a large-print farm is not required to produce high-quality work. Many hobbyists successfully develop excellent projects using a single desktop printer. The process simply takes longer, especially when large prototypes or complete armor sets require dozens of individual print jobs. Patience is often just as valuable as additional hardware.

For our production workflow, printers such as the Bambu Lab P1S, Bambu Lab A1, and larger-format machines like the Bambu Lab H2D provide an excellent balance between price, reliability, print quality, and production speed. In our opinion, similar printers from other manufacturers can also produce excellent results, provided they are properly calibrated and maintained.

We usually print these prototypes using standard gray PLA filament. Since these parts are intended only for evaluating fit and proportions, expensive engineering materials such as carbon-fiber-reinforced filaments provide little practical benefit at this stage. Gray filament also has another advantage: surface imperfections, layer lines, and printing artifacts are generally easier to identify than on very dark or brightly colored materials.

It is also worth noting that these prototypes are not printed with the same settings we would use for functional parts. Our goal is not to maximize strength, durability, or perfect lines. Instead, we optimize the print for speed while using enough wall thickness and infill to produce a stable model suitable for fitting, assembly, and visual evaluation. Once our prototype has served its purpose, the project moves forward with any necessary refinements before the final master models are prepared.

Step 5. Improving 3D Model
How It's Made - Improving 3D model

Producing a physical prototype is only part of the development process. In many cases, the first assembled version immediately reveals opportunities for improvement that would have been difficult, or even impossible, to identify while working only with the digital model.

This stage is where experience becomes just as valuable as software. Once the printed prototypes are assembled and evaluated, our team carefully reviews every component from both manufacturing and practical perspectives. We look at how individual parts fit together, how they move with the body, whether decorative elements interfere with mobility, and whether the overall proportions still match the original vision once the project exists as a physical object.

The development of our Flower Knight Cuirass armor is a good example of this iterative process. Throughout the sculpting stage, our artists regularly shared updated versions of the model with the rest of the workshop. Team members with practical LARP experience provided continuous feedback drawn from years of wearing armor at festivals and events. Rather than focusing solely on appearance, many discussions centered on comfort, movement, visibility, transportation, and long-term wearability.

Sometimes the changes that we made were relatively small. A decorative element might be repositioned, an edge softened, or an attachment point moved slightly to improve assembly. In other cases, larger adjustments were necessary to improve mobility or make individual parts easier to manufacture. Although these revisions may appear minor on screen, they often have a significant impact on how the finished equipment performs during real use.

This collaborative workflow continues until both the artistic vision and the practical requirements are satisfied. Making changes at this stage is considerably faster and less expensive than modifying completed master models or rebuilding silicone molds later in the production process. For that reason, we prefer to spend additional time refining the digital model before moving forward.

Step 6. Final Approval With The Client
How It's Made - Final Approval of the concept

Once the revised model meets both visual and practical expectations, the project we are working on enters its final review stage. For our custom orders, the updated model is presented to the client for approval, ensuring that everyone shares the same understanding before production continues. Internal projects follow a similar process, with the production team reviewing the final design before giving it the green light.

Only after this approval via e-mail (which grants us and the client deal protection on the design) is complete do we prepare the files for high-resolution MSLA printing. By this point, the project's proportions, construction, assembly methods, and overall appearance have been carefully evaluated, allowing the manufacturing process to proceed without stress. Note that further changes are not possible at this stage without a price change!

Step 7. Resin Printing
How It's Made - Resin print

Once the digital model has been fully approved, the project enters one of the most important stages of the production pipeline: creating the final master models. These masters form the foundation for every subsequent silicone mold, meaning their quality directly influences every casting produced in the future.

For this stage, we use high-resolution MSLA resin printers rather than FDM technology. Although both types of printers play important roles in our workflow, they serve very different purposes. FDM printers are ideal for rapid prototyping and evaluating proportions, while MSLA printers are used whenever maximum detail and surface quality are required.

Compared to FDM printing, MSLA technology produces significantly smoother surfaces, sharper edges, finer decorative details, and much higher dimensional accuracy. This level of precision is especially important for armor projects, where engravings, layered surfaces, ornamental elements, and fine textures must all be reproduced faithfully before mold-making begins.

In our workshop, we currently use machines such as the Elegoo Saturn 4 Ultra 16K and the Phrozen Sonic Mega 8K V2. Based on our experience, printers with 8K-class resolution already provide more than enough detail to produce professional master models for silicone mold making. At the same time, the 3D printing industry continues to evolve rapidly, with new machines offering higher resolution, improved reliability, and larger build volumes every year.

For us, a company, however, building volume is often a more important consideration than resolution alone. The ability to print larger components as a single piece reduces assembly work, minimizes potential alignment issues, and preserves continuous surface details that would otherwise need to be reconstructed after joining multiple parts. This becomes particularly valuable when producing large LARP helmets, polyurethane breastplates, pauldrons, or other oversized components.

That said, not every workshop requires industrial-scale equipment. Smaller desktop resin printers are perfectly capable of producing excellent master models for many projects. Choosing the right machine depends largely on the size of the objects being produced rather than simply purchasing the highest-resolution printer available.

Investing in a resin printer can also create opportunities beyond internal production. Many workshops eventually discover that, in addition to developing their own products, they can also offer professional 3D printing services to artists, prop makers, game studios, and other creators who require high-quality resin prints for their projects.

Once the master models have been printed, cleaned, fully cured, and inspected, they are ready for one of the most important stages of the entire manufacturing process: creating the silicone molds that will reproduce every detail of the original sculpt.

Step 8. Silicone Mold Making
How It's Made - Making a silicone mold for the future armor part

Once the resin master models have been fully printed, cleaned, and post-processed, they are ready for one of the most important stages of the entire manufacturing workflow: silicone mold making. In our opinion, this is also one of the least understood parts of the process from a customer's perspective. Most people see only the finished equipment without realizing that much of its final quality is determined long before the first casting ever takes place.

At LARPSHOPKEEPER, we primarily use brush-on platinum silicone systems, including products from Smooth-On and local brands that are less popular on the global market. Instead of pouring silicone around the master model, multiple thin layers are applied by hand (with brushes), gradually building a flexible mold that faithfully captures every surface detail. This approach allows even the smallest engravings, layered textures, scratches, ornamental details, and sharp transitions to be reproduced with remarkable accuracy.

Usually, we start with the first layer using Mold Star 30 (Smooth-On product), followed by several layers of Rebound 25 (also a Smooth-On silicone). Each layer has a specific purpose, gradually strengthening the mold while reducing the risk of trapped air, weak spots, or surface imperfections. Every new layer is applied only after the previous one has fully cured, making patience just as important as technical skill during this stage.

One of the greatest advantages of silicone mold making is repeatability. Once a mold has been completed successfully, it becomes possible to reproduce identical parts with consistent dimensions and surface quality. This is particularly important when producing complete armor sets, replacement components, matching equipment for NPC teams, or larger production runs where every part needs to fit together precisely.

Although silicone molds may appear relatively simple on the surface, they represent a significant investment of time, experience, and money. Any small imperfection introduced at this stage may be reproduced in every future casting. For that reason, we prefer to spend additional time producing a high-quality mold rather than correcting avoidable defects later in the manufacturing process.

Because silicone remains flexible after curing, it cannot support itself during casting. Before the mold can be used for production, it needs a rigid outer structure that preserves its shape and keeps every surface perfectly aligned. That brings us to the next stage of the workflow: creating the mother shell.

Step 9. Creating The Mother Shell
How It's Made - Creating mother shell for silicone molds

Even after our silicone mold has fully cured, it still cannot be properly used for production on its own. Although every detail of the original sculpt has been captured, the mold remains very flexible and would easily deform during casting without additional support. Even slight movement of the mold can affect symmetry, edge alignment, and the overall accuracy of the finished part.

To prevent this, a rigid outer support shell, commonly known as a mother shell or support jacket, is built around the silicone mold. In our workshop, these shells are typically produced using inexpensive epoxy-based materials by simply applying them with a brush around the silicone part. This provides the rigidity needed to keep the mold perfectly aligned throughout the casting process. We recommend having at least 5 mm of the shell thickness all around.

The purpose of the mother shell goes far beyond simply holding the mold together. It preserves the exact geometry of the original sculpt while polyurethane resin is poured, fiberglass reinforcement is positioned, and the mold is handled during production. This becomes especially important when manufacturing large components such as breastplates, helmets, pauldrons, or multi-part armor sets, where even a small deformation can affect how different pieces fit together after assembly.

From our experience, investing additional time in a well-designed support shell saves considerably more time later in production. If the mold shifts or changes shape during casting, the resulting part may require extensive correction or, in some cases, need to be produced again. Preventing these problems at the tooling stage is always more efficient than trying to fix them after the casting has cured.

A properly constructed support shell also helps extend the service life of the silicone mold itself. Because many molds are reused over dozens of production cycles, maintaining stable geometry is essential for achieving consistent quality from the first casting to the last.

Together, the silicone mold and its rigid support shell become the foundation of the entire casting system. Every part produced afterward depends on the accuracy established during these two stages.

Step 10. Preparing The Mold For Casting
How It's Made - Preparing the mold for the cast

Before casting begins, every mold must be carefully prepared. Although this stage is relatively quick compared to sculpting or mold making, it plays an important role in achieving consistent results throughout the production process.

The silicone mold is first cleaned and inspected to ensure that no dust, cured silicone residue, or other contaminants remain inside. It is then assembled inside the rigid mother shell, where every section is aligned and securely fastened before casting begins. If the shell consists of several parts (for bigger armor parts), we fix them together with bolts and nuts.

Depending on the materials and mold design, a suitable release agent may also be applied to help protect the mold and simplify demolding after curing.

At the same time, fiberglass cloth is prepared in advance. Every reinforcement piece is cut to size before any resin is mixed, allowing the casting process to proceed without interruption. Since polyurethane resin has a limited working time, having all materials ready beforehand helps avoid unnecessary delays and improves overall consistency.

Once everything has been checked and prepared, the mold is ready for the most important stage of the entire workflow: composite casting with polyurethane resin and fiberglass reinforcement.

Step 11. Casting Resin With Fiberglass Reinforcement
How It's Made - Casting PU resin into the mold

After weeks of design, digital sculpting, prototyping, and mold-making, the project finally reaches the stage where it begins to take shape as a physical object. This is the point where all previous production steps come together and where the quality of every earlier decision starts becoming visible.

In our workshop at LARPSHOPKEEPER, polyurethane resin is combined with multiple layers of fiberglass cloth to create equipment that remains lightweight while being durable enough for active LARP use.

Based on our experience over the years, fiberglass reinforcement is one of the most important parts of the entire production process. Polyurethane resin alone can reproduce excellent detail, but without reinforcement, larger components may become too brittle or vulnerable to repeated stress over time. Fiberglass distributes loads throughout the structure, significantly improving rigidity, durability, and long-term wear resistance.

Workshop Note

Every workshop eventually develops its own casting methods, reinforcement layouts, and material ratios. The workflow described in this guide reflects the techniques that have consistently delivered the best results for our team over years of experimentation with various materials and manufacturing approaches.

Our production team has experimented with numerous reinforcement methods over the years. We tested fiberglass mat, different cloth densities, materials from several manufacturers, and even experimented with carbon fiber as part of our standard production workflow. While each material offered certain advantages, fiberglass cloth consistently delivered the best overall balance between durability, flexibility, weight, surface quality,  price, and production reliability. Even today, whenever we discover new suppliers or materials, we continue to evaluate them to determine whether they offer meaningful improvements to our manufacturing process.

The casting itself is performed in several stages. We always begin by applying a thin layer of polyurethane resin directly into the prepared mold without any fiberglass reinforcement. This first coat allows the resin to flow into every engraving, texture, sharp corner, and decorative element, capturing even the finest details of the original sculpt. At this stage, there is only one opportunity to reproduce these details correctly. Any trapped air or imperfections introduced during the initial layer are likely to remain visible on the finished casting.

Once the first layer reaches the appropriate stage of curing, fiberglass reinforcement is gradually introduced. Instead of using large continuous sheets, we usually cut the cloth into many smaller pieces of different sizes and shapes. This allows the material to conform much more easily to complex curves, deep recesses, and intricate fantasy designs while remaining in close contact with the mold surface.

Whenever possible, we slightly overlap neighboring pieces of fiberglass cloth. These overlaps help distribute loads more evenly throughout the finished part and create additional reinforcement where individual sections meet. However, this is not always physically possible. Very narrow decorative details, thin borders, or intricate ornamental patterns sometimes leave no room for proper overlap.

Situations like these are among the reasons we already consider manufacturability during the 3D sculpting stage. Whenever possible, extremely fragile details are redesigned or simplified before production begins. Sometimes, however, preserving the original artistic vision is more important than making every area ideal for reinforcement. In these situations, increasing the wall thickness of selected areas often provides the additional rigidity needed to protect delicate sections without noticeably changing the overall appearance of the finished piece.

Careful control over resin quantity and fiberglass saturation is equally important for mass-produced products. Too much resin adds unnecessary weight, while insufficient saturation may reduce structural integrity. Over the last few years, we have documented our production formulas, material ratios, and successful casting techniques, allowing us to achieve consistent results across different projects that we have made. As a general reference, most of our standard castings are approximately 4-5 mm thick, although this varies depending on the function of each individual component and the amount of reinforcement required.

In our experience, the combination of polyurethane resin and fiberglass cloth is one of the key reasons modern composite equipment has become a practical solution for long-duration LARP events, festivals, and repeated field use.

Once the resin has fully cured, the mold can finally be opened. This is always one of the most rewarding moments of the entire workflow, as weeks of design, planning, printing, mold-making, and preparation finally result in the first finished casting. Only then can we inspect the part, evaluate the casting quality, and continue with the next stages of production.

Step 12. Releasing The Cast From The Mold
How It's Made - Releasing polyurethane cast

Once the polyurethane resin has fully cured, the mold can finally be opened, and our cast part can be carefully removed. Although this may seem like a straightforward step, it requires patience and attention to detail. Freshly cast pieces can still retain some flexibility (depending on the resin curing time), while thin decorative elements or delicate edges remain more vulnerable until the post-processing stage is complete.

Careful demolding is important not only for protecting the casting itself but more for preserving the silicone mold for future production. Excessive force or improper handling may damage fine details or unnecessarily shorten the mold's lifespan. Since many molds are reused multiple times (sometimes dozens of times), every part is removed as carefully as possible.

The first cast piece also provides an opportunity to inspect the overall quality of the production process. Surface finish, detail reproduction, mold alignment, and reinforcement quality are all checked before the project moves to the next stage.

Step 13. Post-Processing
How It's Made - Cleaning seam lines and sanding

Every casting requires a certain amount of post-processing before it is ready for painting. During this stage, excess material left from the casting process is carefully removed, including flash, sprues, overflow areas, and mold seams. Edges are trimmed, transitions are refined, and the entire surface is inspected for small imperfections (usually air bubbles) that may require additional attention.

Depending on the project's complexity, several individual components may also need to be assembled, bonded, or given minor adjustments with a Dremel before moving forward. Although these corrections are usually quite small, they do not play the last role in achieving a clean and legit final appearance.

This stage is also the final opportunity to inspect every part before surface preparation begins. Any remaining imperfections are much easier to correct now than after primer and paint have been applied.

Once the surface has been cleaned, refined, and inspected, the armor is ready for priming and the finishing stages that gradually transform a raw casting into a completed piece of equipment.

Step 14. Priming
How It's Made - Priming parts with automotive primers

Before painting begins, every part is carefully prepared with a suitable primer. Although this stage may seem relatively simple, it has a significant impact on the quality of the finished paintwork.

Our standard workflow uses a two-component automotive primer system. Primer creates a uniform surface that improves paint adhesion while making small imperfections much easier to identify. Tiny scratches, sanding marks, mold seams, or surface defects that were difficult to notice beforehand often become visible after the first coat of primer. This provides one final opportunity to correct them before color is applied.

The amount of preparation varies from project to project. Simpler parts may be ready after a single primer application, while highly detailed components often require several rounds of priming, sanding, and inspection before they meet our quality standards. Although this process takes additional time, it has a significant impact on the final appearance. We typically begin with a light gray two-component automotive primer, because its neutral color highlights even the smallest surface imperfections before painting begins.

Step 15. Building The Fastening System
How It's Made - Adding leather straps

By this stage, the project is almost complete, but it still needs to become wearable equipment rather than simply a collection of finished parts. This is where the fastening system kicks in.

Every project requires a slightly different attachment system depending on its size, weight, and intended use.

In our workshop, we primarily use vegetable-tanned leather (veg-tanned leather) for straps and fastening systems. We prefer it because it combines excellent structural strength with predictable behavior during cutting, edge finishing, riveting, and long-term use. It also develops a natural patina over time while remaining easy to maintain or replace if individual straps eventually wear out.

Workshop Note

Since many of our products are manufactured repeatedly, we also create dedicated cutting templates for leather components whenever possible. This helps maintain consistent dimensions while significantly reducing production time for future builds.

Large armor sets require particular attention to both weight distribution and adjustability. Proper strap placement helps distribute weight more evenly across the body, reducing unnecessary movement during walking, roleplay, or combat. Because every player has slightly different body proportions, most fastening systems are designed with some adjustment, allowing the equipment to fit more comfortably and making future maintenance or replacement of individual straps much easier if needed.

Step 16. Creating The Padding System
How It's Made - Seving paddings for the PU armor

While the hard composite components provide structural strength, the padding system is largely responsible for long-term comfort. In our experience, even the best-designed equipment can become uncomfortable during a multi-day event if the padding is not carefully planned. 

Each padding set is designed to match the shape of its corresponding component. Its purpose is not only to make the equipment more comfortable but also to distribute pressure more evenly, reduce pressure points, improve stability, and minimize unwanted movement during walking, roleplaying, or combat.

Over the years, we have tested different padding materials, thicknesses, and attachment methods during real LARP events. These experiences have helped us refine our designs and better understand which solutions remain comfortable after many hours of continuous wear rather than just during a short fitting session.

To make future maintenance easier, we primarily use Velcro attachment systems. This allows individual padding pieces to be removed for cleaning, repositioned to achieve a better fit, or replaced if they eventually wear out after years of regular use.

Although padding is one of the least visible parts of the finished equipment, it has a surprisingly large impact on the overall wearing experience. For us, comfort is just as important as appearance, and the padding system plays a significant role in achieving that balance.

Step 17. Painting And Finishing Process
How It's Made - Painting process

At LARPSHOPKEEPER, painting is one of the most creative stages of the entire workflow. At this point, the raw composite casting finally begins to develop its own personality, transforming into equipment that looks as though it belongs in a living fantasy world rather than a production workshop.

Our painting process combines techniques borrowed from several different hobbies and industries. Long before producing full-size LARP equipment, members of our team spent years painting scale models and miniature wargaming figures. Although the size of the projects has changed dramatically, many of the same principles still apply. Understanding light, shadow, color transitions, weathering, and surface textures on miniatures has proven invaluable when painting full-scale armor.

Depending on the project, the finishing process may include acrylic base coats, oil washes, metallic effects, weathering, battle damage, dirt accumulation, rust simulation, and many other techniques. Rather than relying on a single layer of paint, multiple thin coats are gradually built up to create depth, contrast, and a more convincing appearance.

One advantage of this approach is that two identical castings can look completely different after painting. Color choices, weathering intensity, and artistic style all influence the final result, allowing every project to develop its own unique character.

Once the painting is complete, the parts are not immediately ready for assembly. We usually allow the paint to cure for one to two days before handling the finished components. If oil-based products have been used for weathering or special effects, we generally allow an additional day of curing to ensure the surface has fully stabilized before moving to varnishes.

The completed finish is then protected with a suitable matte or gloss clear coat, depending on the desired appearance. Besides enhancing the final look, this protective layer improves resistance to abrasion, moisture, and general wear that naturally occurs during transportation, combat, and repeated use at LARP events. We highly recommend using gloss automotive clear coat (which creates a “wet” effect on the surface) because it is highly durable!

Step 18. Photography And Shipping
How It's Made - Final photos before shipping

Before every order leaves our workshop, it goes through one final stage: photography and quality inspection.

Photographing the finished equipment serves several purposes. It allows us to document completed projects, update our portfolio, prepare product images for our website, and, when required, share the finished result with the customer before shipping.

Photography (and video) is also one of our final quality-control tools. Looking at a project through the camera often reveals small details that are easy to overlook during production, such as paint consistency, symmetry, assembly alignment, or minor imperfections that may still require correction. And only after the final inspection is complete is the entire costume carefully packaged and prepared for worldwide delivery.

Final Thoughts

From the outside, our armor may appear to be just another finished product. But in reality, every piece represents weeks of planning, manufacturing, testing, and craftsmanship long before it reaches its owner. Throughout these massive blocks of text and pictures, we've walked through the complete workflow used in our workshop, starting with the initial character concept and continuing through digital sculpting, prototyping, mold making, composite casting, finishing, assembly, and final inspection. Every stage exists for a reason. Some improve structural strength, others increase comfort, while many help preserve the original artistic vision without compromising practicality during real LARP events and ren faires.

In addition, over the years, our team has continuously refined this workflow by testing new materials, improving production techniques, and gathering feedback during actual events and festivals. Many of the methods described in this guide are the result of countless prototypes, production improvements, and lessons learned through real-world experience rather than theory alone.

We do not believe that modern PU armor is meant to replace traditional steel or leather armor. Instead, it offers another approach for players who value lower weight, greater mobility, easier maintenance, and the freedom to create highly detailed fantasy designs while remaining comfortable during long events.

Whether you are interested in the manufacturing process, planning your own project, or simply curious about how modern LARP equipment is made, we hope this guide has provided useful insight into the work that takes place behind the scenes.

After all, every finished piece begins with a single idea. Everything that follows is the result of creativity, engineering, craftsmanship, and countless hours of work of a whole team dedicated to bringing that idea into the real world.