3D Printing: Cosplay, Decor, Props – Planning & Implementation

Lisa Ernst · 23.11.2025 · Technology · 5 min

The armor part looks perfect on screen, but at the convention, it lasts for exactly two photos – then the bracket breaks or the spear droops like a wet spaghetti. That's annoying, especially when you've spent days printing, sanding, and painting.

In our workshop at 33d.ch, we hear stories like these all the time. Cosplayers come with impressive 3D models that, technically, were never planned for everyday convention use: parts are too heavy, connectors are too weak, the printer is too small for the monster sword, or transport by train becomes a real challenge.

If you focus on material selection, segmentation, and reinforcement from the start, a pretty STL becomes a prop that survives a full convention day, remains transportable, and looks like metal or wood in photos. In this guide, we summarize how we at 33d.ch plan cosplay props and decor with FDM 3D printing – with examples from our workshop and links to proven community resources.

Quelle: Own Representation

Basics of 3D Printing for Cosplay

For cosplay props, we usually work with FDM printers because they deliver robust, repairable parts. Three basics will very early on determine whether your project is relaxed or stressful: build volume, material, and the internal structure of the part.

Estimate Build Volume Realistically

The size of a 3D printer's build volume presents an initial limitation. Standard FDM printers with a build volume of approximately 220 × 220 × 250 mm require segmentation of large parts like swords or helmets ( Ultimaker). ). In practice, we therefore almost never plan large props "in one piece," but think of them from the start in sensible segments that fit the build volume and can be cleanly connected later.

Material Selection for Armor, Props & Decor

Material choice significantly impacts weight and durability. PLA is a common filament that can be printed at relatively low temperatures and delivers detailed results, but it is brittle and less temperature-resistant ( FormFutura). ). PETG is more resistant to impact and breakage, making it more suitable for armor parts or staffs that are exposed to bumps ( SUNLU 3D Druckmaterialien). ). In our workshop, PLA often ends up in filigree ornaments, while PETG is used for parts that can afford to be bumped into something.

For projects where weight is a major factor – such as shoulder pads, large weapons, or voluminous decor – lightweight filaments like LW-PLA can be used. These reduce weight by up to around 65% compared to normal PLA and are easy to work with ( ColorFabb). ). We use such filaments primarily when a part protrudes far from the body or is worn for hours.

Infill, Wall Thicknesses & Orientation Explained Briefly

Durability depends not only on the filament but also on wall thicknesses, infill, and layer orientation. Infill, simply put, is the interior of the part – how full the body is printed between the outer walls. Mechanically stressed zones require higher wall counts and an infill of about 20-30%, while decorative parts can be made significantly lighter with thinner walls and low infill ( eufyMake).

Typical Starting Values (always test with your own printer and material):

Temperatures and printing speeds can vary significantly depending on the printer, nozzle, and filament manufacturer – when in doubt, a quick test print is more worthwhile than reprinting an entire prop later.

Quelle: voxelmatters.com

After Printing: Individual components being prepared for further processing.

Planning and Assembly

Once size and material are roughly determined, the actual "construction planning" begins. At this point, it's decided whether you can assemble cleanly later or if you'll end up with improvised gluing sessions on the eve of the convention.

After determining the prop size, the segmentation planning begins. 3D models are often separated along natural edges like panel seams or decorative lines to integrate gluing points inconspicuously. Platforms like Printables, Thingiverse or MyMiniFactory offer many pre-made cosplay models. In many cases, we at 33d.ch slightly adapt such models, for example, by adding connectors or planning hollow spaces for carbon rods.

Quick Checklist Before Printing

• Check Scale (Helmet actually fits? Weapon convention-safe?).
• Plan Segmentation (Maximum build volume vs. sensible division lines).
• Plan snap-fit or screw connections instead of just butt-gluing.
• Include reinforcements like fiberglass or carbon rods.
• Consider Transport (Train, Car, Hand Luggage) – a completely rigid 2-m spear rarely makes sense.

Gluing and Reinforcing Parts

For gluing 3D printed parts, cyanoacrylate adhesives (super glue), solvent-based adhesives, and two-component epoxy resin have become established ( Original Prusa 3D Printers). ). Super glue gel is suitable for quick connections in PLA projects, epoxy resin for maximum strength, for example, at highly stressed connection points ( Snapmaker).

Clean preparation of the bonding surfaces is crucial. Roughening with fine sandpaper and cleaning with isopropanol significantly improves adhesion ( Fuji Technology). ). Super glue should be applied thinly and evenly, followed by about 10-30 seconds of firm pressing of the parts ( JLC3DP). ). Well-prepared surfaces and products like cyanoacrylate, contact adhesive, or epoxy resin result in stable, sandable connections for PLA ( Instructables).

For long weapons and staffs, pure bonding is often insufficient. An internal core of fiberglass or carbon rods, guided through the segments, increases flexural strength and fracture resistance without significant weight gain ( FormFutura). ). In one of our first spear projects, we underestimated this step – the part looked great but was ruined upon the first accidental ground contact. Since we consistently reinforce, this problem has practically disappeared.

Rough Guide for Adhesives (From Practice):

Quelle: 3ddruckmuenchen.com

Detail and Precision: 3D printing enables impressive cosplay elements.

Surface Treatment and Painting

Raw FDM prints rarely look like "fantasy metal" or "aged wood." However, with a little patience, this can be surprisingly well disguised – and this is exactly where "okay" often separates from "wow" for cosplay props. After gluing, layer lines are covered with filler spray, the surface is sanded, puttied, and primed again. This process is also described in detailed finishing guides ( twincitiesgeek.com, Markforged). ). Good primer smooths out irregularities and improves paint adhesion ( Formlabs). ). In our workshop, it has proven beneficial to plan for two thin coats of filler and sanding rather than trying to "magically fix" everything in one go.

Typical Workflow in Our Workshop

1. Roughly sand layers (e.g., 120-180 grit).
2. Spray filler primer and let it dry completely.
3. Fill unevenness with putty, sand again.
4. Prime again until the surface looks even.
5. Apply base colors, washes, and dry brushing.

Metallic areas can be built up with acrylic paints and an airbrush in multiple thin layers, emphasized with a dark wash, and highlighted with dry brushing to simulate worn metal. An Instructables tutorial offers a step-by-step guide to simulating various materials like rust or glass using painting techniques ( Instructables).

On YouTube, you can find complete workflows from printing to painted props, demonstrating the entire finishing process from sanding and filler primer to an airbrush finish ( YouTube). ). Special videos for cosplay props show how 3D printed parts can be quickly made convention-ready with spray paint and simple weathering ( YouTube). ). A basic course explains the path from the print bed to the finished, painted part for beginners ( YouTube). ). We often recommend our customers watch one or two such videos alongside their first major project – it saves a lot of trial and error.

Practical Example: 1.9m Energy Spear for a Convention

At 33d.ch, we created a futuristic energy spear about 1.9m long for a convention appearance. We divided the 3D model into eight segments: four for the shaft, three decorative intermediate pieces, and a complex spearhead. This allowed all parts to be manufactured on a standard printer and stably connected later.

The shaft was printed from PETG to ensure a balance of flexibility and impact resistance ( Kingroon 3D). ). Decorative elements and the spearhead were made from PLA, as detail accuracy was more important than flexibility here ( FormFutura). ). We often use this combination: PETG for the "skeleton," PLA for the look.

The core of the spear consisted of two continuous 8mm carbon rods. The PETG shaft parts enclosed the rods and were additionally connected via tenon and mortise joints. Bonding surfaces were roughened, dusted, and glued with cyanoacrylate gel. Two-component epoxy was used at particularly stressed transitions to create a stable connection ( Original Prusa 3D Printers, Snapmaker). ). After an intensive test day outdoors – including accidental bumps – only minimal paint touch-ups were needed.

The finish included covering the layer lines with filler spray, sanding, puttying, and re-priming. The color scheme was built up with acrylic paints and airbrush in multiple thin layers, emphasized with washes, and highlighted with dry brushing to simulate worn metal.

Quelle: 3d-grenzenlos.de

Various 3D printed cosplay parts ready for further processing.

Quick Conclusion for Your Next Cosplay Project

From our projects and proven community guides, a few clear learnings can be derived:

• Choose material suited to its purpose: PLA is very suitable for detailed elements, PETG and lightweight filaments like LW-PLA have advantages for highly stressed or large parts. Material comparisons from manufacturers like FormFutura, Kingroon 3D and ColorFabb provide a good initial orientation.
• Plan segmentation, gluing, and reinforcement early: Clean segmentation, well-thought-out gluing points, and internal reinforcements transform individual parts into a stable whole. Practical gluing guides and tests recommend combinations of super glue, epoxy resin, and good surface preparation ( Original Prusa 3D Printers, Snapmaker, Instructables).
• Don't underestimate the finish: The transition from raw blank to painted prop requires patient sanding, filler primer, priming, and targeted paint layers. Expert articles and tutorials show how visible layers are transformed into seemingly solid metal, aged wood, or painted plastic ( Formlabs, Sinterit 3D Drucker & Zubehör, twincitiesgeek.com).
• Practice over Perfection: Better a robust, lightweight prop with a few minor paint flaws that you can wear comfortably, than a hyper-realistic part that breaks after an hour. In practice, we often see that second or third versions turn out significantly better – so plan enough time for learning curves.

This is how an idea, STL files, and filament become painted cosplay props that you can wear at conventions, impress in photos, and last through multiple events.