When harvested, the wet material is like a spongy mat full of liquid culture. While drying it releases and let evaporate all the liquid in- side, shrinking in thickness. During this process the nanocellulose filaments bind together creating a strong unique layer, sealing any cut or small hole in the meantime. This ability to “self-seal” and stick together can be used for stratification. In this way is possible first of all to gain a better control on the final material, having the possibility to adjust the thickness also after the growth overlapping thinner cellulose layers. Moreover, since the microbial cellulose is translucent, this technique can be used to control and modify the transparency of the material –the thicker it is, the duller and darker is its colour.

The final morphology of the material will be obtained after the drying phase, since it can be still shaped while wet. Placing it on an embossed surface while drying is possible to create folds, plisse, bumps, and even 3d shapes. Adittionally, it is possible to imprint any texture on the material changing the flat surface used for the drying stage, since its surface texture will be transferred to the material surface. Extremely smooth plastics such as acrylic panels will result in a glossy finish, while rougher surfaces such as polypropylene, styrofoam or wood will result in a matte and more “natural” skin-like texture.

Microbial cellulose can be also turned into a pulp and mixed to other materials to create bio-composites. Blending the nanocellulose layer however, means to break down all the nano filaments into smaller parts as happens for paper recycling, resulting in a weaker material with a lower tensile strength. The cellulose pulp can be used as a binder to make composites out of waste – with tea leaves, coffee grounds, etc –, or as basic component of the composite to which additives can impart new properties.

Microbial cellulose is a porous and highly hydrophilic material. This makes it barely resistant to water and humidity, but on the other side makes it behave like a sponge: it can absorb other fluids that can be embedded in the material and later released. Its absorptive properties can be used also to dye the material after the harvest. The traditional dyeing techniques which use hot water baths are not the best way to colour the material, since water degrades it making it less flexible, more brittle and fragile. The best way to get coloured nanocellulose is during growth. If you want to dye it at a later time, you can soak it in an acidic dye as the culture medium, this will make the colour absorbed by the material without degrading it.

Porosity and hydrophily can be reduced through surface treatments, with the aim of making the material more durable because more resistant to environmental conditions as changes in humidity etc. Many surface treatments have already been experimented with positive results such as beeswax or turpentine. However, they are often animal or solvent-based and therefore unethical and harmful for the environment. The best option appear to be vegetable oils such as tung oil, commercial name of an oil extracted from the tung tree – Vernicia fordii – which polymerises when exposed to hair, historycally used in ancient China to waterproof paper umbrellas or wooden boats. When used to finish microbial cellulose, it gives the material a matte and smooth finish, preserving it from degradation.

The material can be processed through laser cutting and engraving. Since it has a variable and not perfectly regular thickness, in order to get a better result each sheet of material needs to be tested individually to establish the proper parameters on the machine. The laser cutter can be used for different purposes besides cutting out two-dimensional shapes out of the cellulose sheet, such as realising auxetic textures that can modify the material behaviour creating three-dimensional morphologies with a two-dimensional piece of material; engraving fold lines to facilitate the use of folding techniques such as Miura-Ori; or engraving text and symbols.

The porosity of the material makes it suitable for printing, similarly to traditional paper. Inks commonly found on the market, even the water-based ones, are synthetic and contain substances damaging to the environment. Natural inks are a niche product produced mainly by small artisans, not so easy to find. One of the reasons why natural inks are not so common is their short-lasting compared to synthetic ones, echo of the idea of permanence, eternity and immutability which characterised the industrial culture of the last centuries. This characteristic however, is useless when working with biodegradable materials which will fade over time together with the ink, making ephemeral compostable inks the best suited for printing purposes.