Introduction

Our masks are inspired by the simplicity of Noh Theater masks and abstract Bauhaus costumes. They combine several natural materials as well as a variety of technologies.

The design evokes the essence of an insect spirit, while leaving room for open interpretation. We chose a chitosan and natural fiber fabric composite to form a robust structural base for the masks, while the agar foil in combination with leaf skeletons and natural dye contributes contrasting decorative elements. We envision these two materials for use in unique fashion designs.

1.0 / Research + Testing Agar Bioplastic

Agar-based bioplastic can be used to produce a thin, flexible, and surprisingly durable film. While it resists tearing from the center, it tends to rip easily when pulled from the edges. In this project, we aimed to strengthen the film by incorporating plant fibers. We were particularly intrigued by leaf skeletons, not only for the intricate, delicate aesthetic they offer, but also for their potential functional benefit. The network of leaf veins could serve as a natural rip-stop, helping to prevent small tears from spreading across the film.

Questions: Can agar-based bioplastic film be…

• structurally reinforced? Yes

• reinforced using natural fibers such as nettle? Yes

• combined with other materials, such as a paper-like molded pulp? Yes

• sewn together? Yes

1.2 / Agar Bioplastic Recipe

• 0,375 g pectin

• 2,5 g agar

• 1,5 g glycerine

• 100 ml destilled H20

Sprinkle pectin and agar onto the surface, and make sure no clumps form. Gently bring to a boil, stirring constantly. Let the solution boil for about 30 seconds, then pour it on onto a sheet of parchment paper in a layer about 5 mm thick. After it hardens, dry it in an oven at 50 °C until a thin foil forms.

1.3 / Leaf Skeletons

To produce leaf skeletons, first collect leaves, in this case the leaves of the chestnut tree. After rinsing them, they are frozen and thawed twice to help rupture the cell walls. Then, they are simmered for 4 to 6 hours in a sodium carbonate solution, which acts like a strong soap to further break down the plant cells. The leaves are then taken out, rinsed in fresh water, and placed on a plate with a little water. Using a paintbrush, the cells are carefully brushed out of the network of veins. After several rinses with cold water, the remaining veins are placed on a plate to dry. The delicate structure can then be embedded in the agar solution to enhance the aesthetic and structural qualities of the film. Once the film is dry, the surface will often have a slight iridescent quality. It is unclear what exactly causes it, but the result is repeatable from one batch of skeletons to the next.

1.4 / Adding Color

The agar film simply begs for color. Standard food-grade dyes will give the film ethereal, transparent colors. Adding natural dyes adds visual texture, as the dyes may not completely dissolve. In the image below, turmeric, sandalwood, red beet, and butterfly pea powder were used to dye the agar solution before pouring it.

2.0 / Research + Testing Chitosan Bioplastic

Chitosan is a naturally occurring polysaccharide derived from the exoskeletons of crustaceans, such as crabs and shrimp, as well as from the cell walls of fungi. It is produced through the deacetylation of chitin, a long-chain polymer of N-acetylglucosamine. We selected chitosan for our second bioplastic formulation due to its non-toxic properties and its relevance to the theme of the ballet, which features insect spirits.

Our initial recipe was obtained from Materiom (https://commons.materiom.org/materials-database/recipe/649c36218e0f06dcab0b7cfd).

Questions: Does chitosan-based bioplastic

• shrink when drying? Yes, a lot

• change with different mixing ratios ? Yes

• Can it be combined with agar and pectin? Yes, quite well

• Can it be reinforced with natural fibers? Yes

• What kind of fibers works best for our project? Coarsely woven jute

• Can it be molded when used with fibers? Yes

Upon attempting to replicate the recipe, we first encountered difficulties in mixing the chitosan with the solution, resulting in a viscous mass. We hypothesized that the original recipe contained a typographical error and attempted to correct it. Following the revised recipe, we successfully obtained a homogeneous solution, which we then applied to two petri dishes at different heights and to a piece of cotton fabric.

After allowing the solution to air dry for a week, we observed that the solution in the petri dishes had shrunk significantly, rendering it impossible to remove. In contrast, the fabric absorbed the solution and became stiffer and more malleable. We folded the fabric in a zig-zag pattern, and it retained its shape without any additional support. The surface of the fabric also became smooth and sticky, but only on surfaces like glass or itself.

In our next experiment, we attempted to combine both our materials by preparing an agar solution and adding vinegar and chitosan in the same ratio as in the latest chitosan recipe. The resulting solution exhibited a jelly-like consistency and was applied to a petri dish, cling film, and already dried agar foil. After allowing the solution to dry for a week, we observed that the solution in the petri dish had shrunk but still retained its jelly-like feeling, resembling human skin. The surface became smooth, and it dried in the form of the petri dish. The solution in the foil also shrunk, but to a lesser extent, and retained its original form and consistency. It began to dry, but the solution with the agar foil became almost foil-like while maintaining its jelly-like consistency.

After an additional week of drying, the solution shrunk further and became hard, losing almost all flexibility and jelly-like consistency. It darkened in color, and we decided to discontinue further experimentation with this formulation.

Molding the mask

The following week, we investigated the moldability of the fabric material by applying it to a mask and gathering the fabric to enhance stability.

We also explored the possibility of attaching fabric pieces using the chitosan solution while molding it inside a mask. To further improve stability, we increased the amount of chitosan in the recipe. We tested different types of fabrics, including cotton and coarsely woven jute. After allowing the fabric to dry for a week, both molding projects were successful, and the fabric retained its shape. However, when attempting to apply a second layer of chitosan solution, the already dried solution dissolved, and the mask made from fabric pieces disintegrated.

Upon comparing the different fabrics, we found that jute performed best with our intended application, and we decided to use it for future experiments. We concluded that fabric would be a suitable component for our bioplastic formulation.

In the subsequent week, we molded a half-face mask using the jute fabric and added color pigment to the mixture. We used the revised mixing ratio with increased chitosan content. After a week, we obtained an extremely sturdy mask with a light blue tone. Following this successful experiment, we decided to proceed with both the fabric and solution and initiated production of our masks.

2.2 / Chitosan Bioplastic Recipe

• 4 g chitosan

• 20 ml 25% vinegar

• 5 g glycerine

• 100 ml destilled H20

Heat water to around 70 deg C then add vinegar. Stir constantly with a blender and slowly add chitosan until a homogeneous solution is obtained. Add glycerine and stir until everything is thoroughly mixed. Dip the fabric into the solution and shape it. Let it dry at room temperature for about a week.

3.0 / Designing and Constructing the Masks

Inspiration and Influences

• abstract shape

• insect spirits

• simplicity of Bauhaus

• Noh Theater masks

• natural materials

• old and new technologies

Sketches

Our goal was to design masks integrating both of our bioplastics for the centennial production of The Triadic Ballet, originally conceived by Oskar Schlemmer. We aimed to preserve an abstract yet organic form, something that could evoke the essence of an insect spirit, while leaving room for open interpretation.

Mask Construction

1) Build forms for the chitosan and fabric mask bases using paper theater masks, lots of tape, and plastic foil

2) Dip fabric into dyed chitosan solution, shape using pins to hold wet fabric in place, let dry

3) Pour agar foil, some with leaf skeletons, some dyed, let dry

4) Laser shapes from pieces of agar foil, cut others out with scissors or blades

5) Add decorative agar elements to the chitosan base with needle and thread!

We created three different mask bases, as shown below.

Planning Embellishments

The image below shows part of the planning process, in which we cut out parchment paper mock-ups to see how the agar film might look when attached to the mask base.

Stitching 

The final step of constructing the masks was to sew everything together. Every sheet, sequin, wing, plastic shield and elastic band is handsewn to each other. We chose needle and thread instead of glue for reasons of quality, sustainability and dedication to include manual labour.

4.0 / Laser Cutting Technique

Laser cutting is a precision thermal cutting process that utilizes a focused laser beam to melt, burn, or vaporize material, creating a precise cut. A CNC system controls the laser's movement, allowing it to follow a pre-programmed path to create complex shapes and designs.

For testing our material in the ability to laser-cut, we chose one basic agar sheet, one with leaf skeletons, and one jute fabric with our chitosan recipe. It took a few tries with different parameters to cut through the basic agar sheet. When using the same parameters with the leaf skeleton sheet, it cut right through. We were able to cut the chitosan jute fabric on the first try using the standard parameters. We also tried engraving both agar sheets, both worked really well with the standard parameters, giving beautiful results. Especially the engraving on the leaf skeleton had interesting results, still showing the skeleton of the leaves.

In the end, we decided to use the laser cutter only on our agar-based bioplastic to produce decorations for our masks. We used both the simple agar sheet and the ones with leaf skeletons, at a speed of 50 mm/s and power between 35% and 15%.

Laser Test

Laser in practical application

5.0 / Vacuum Forming Technique

Vacuum forming is a simplified thermoforming process used to shape thermoplastic sheets into three-dimensional objects. It involves heating a plastic sheet until it becomes pliable, then using vacuum pressure to pull the softened plastic onto a mold, taking on its shape. 

We used our paper masks as a mold to form some plastic mask inserts to have a protective and disinfectant-proof layer between the mask and the face. In the future, having a more flexible, thinner layer would be better fitting for its purpose.

Hygiene will be important for the performers wearing the masks. As the chitosan-basked masks are not waterproof, and the fabric texture makes it impossible to effectively sanitize them, we decided to create plastic inserts to attach to the inside.

6.0 / Final Masks + Résumé

The combination of laser cutting, vacuum forming, and handcraft techniques enabled us to control both form and surface qualities with precision while maintaining a strong material presence. Challenges such as shrinkage or sensitivity to moisture ans mold were expected and resolved through iterative adjustments to recipes and fabrication methods. We balanced aesthetics with functional requirements, and translated the abstract ideas from Thorsten and the Triadic Ballet into contemporary biomaterial applications. The final masks offer a foundation for future explorations of material use in the performing arts and fashion design. 

Overall, we are satisfied with the outcome and hope that the masks will still get the chance to be tested in real performance conditions on stage.