Material Portrait: Vienna Textile Lab

The HEREWEAR sample collection scopes the field of bio-based materials and highlights what challenges and opportunities designers face when engaging with these materials. The 80+ samples in the collection show a range of materials and technologies associated with bio-based textiles and demonstrate innovation at different levels of readiness to market.

The field of bio-based materials is very broad, and some myths and misconceptions are quite common when it comes to sustainability. The HEREWEAR review led to drawing a lifecycle map (Figure 1) for bio-based materials which can support design decision-making when working with local, circular, and bio-based materials. This Bio-based Material Lifecycle Map (BMLM) shows how key innovation that supports environmental impact reduction can take place in different parts of the supply chain. This is a start to a useful discussion involving designers and experts across disciplines to change fashion and textile systems.

This series of posts highlights some exciting materials from the HEREWEAR sample collection through the lens of the BMLM to show how different materials offer different opportunities and challenges when designing for local, circular, and bio-based fashion systems.

Vienna Textile Lab is a start-up developing an innovative method to dye fabric using microorganisms, predominantly bacteria. The focus of this material portrait, therefore, isn’t on the material itself, but rather on this exciting process of natural coloration.

The colour is produced by a range of bacteria present in nature. Vienna Textile Lab source these living organisms through an exclusive partnership with a library of bacteria which are all collected directly in their environment, whether this is a forest, a sandy beach, or a city. The feedstock in this process is then literally the food that keeps these bacteria alive and induces them into producing colour. As the process is currently at a lab scale, the feedstock used is a standardised medium, but with scale, it would be expected that this food could be in the form of organic waste from human food production or other agricultural processes (1).

Microorganisms/Bacteria grow and divide via a process generally termed fermentation (2) during which colour is produced. It is key to maximise the efficiency of this process to support high yields for the bacterial colour. This growth phase can happen either directly on fabric or in a cultivation tank to produce a dye extract that can later be used in conventional dyeing processes.

After the fermentation, the autoclave process ‘kills’ the bacteria, which are separated subsequently, so that only the colour remains and there is no bacterial residue. This responds to some consumer worries that the bacteria might be harmful to the wearer. It points to some barriers to the adoption of these technologies going beyond the innovation itself and touching on psychological blocks.

The bacterial dye process works on a very wide range of fibres including conventional natural fibres like cotton and wool, or man-made cellulose fibres. More surprisingly, the process has been proved to work on synthetic fibres such as polyester. While the use of natural dyes such as these bacterial dyes is often associated with non-fossil-based resources, the demand for polyester and its versatile qualities is undeniable. Different fibres dye differently. For example, wool soaks up a lot of water and dyestuff in its dyeing process, whereas polyester can generally be dyed in low-water processes. This also applies to the bacterial dye process. This points to some interesting tensions between the use of synthetic fibres for efficiency and the potential of natural fibres in bio-based systems.

Vienna Textile Lab’s work is inherently connected to the finishing phase of the materials, where they can be dyed (3) using this innovative process. The aim of the company is to achieve a point where the bacteria can produce an extract ready to be sold to conventional dye houses as a drop-in substitute for synthetic dyes. This would be a timely response to bans and regulation imposed on this part of the life cycle to reduce overall environmental impacts. For now, exciting results have been achieved by letting the bacteria grow directly on the cloth, creating beautiful patterns that are favoured by designers (Figure 2).

While it is still early to collect feedback on the use of clothing dyed in this process, tests are showing that the colour withstands normal washing temperatures. Innovations in dyeing can be challenging as industry standards require high levels of consistency which can be hard to achieve with alternative processes. However, mindsets are shifting, and the industry is starting to open up to solutions that might behave differently from synthetic dyes in the use phase (4). The scale at which the Vienna Textile Lab process operates can also make it an option for overdyeing as a lifecycle extension strategy (5). This shows a systemic shift that can be afforded by this technology.

The end of life, as often, will be very dependent on the other materials and processes involved in the final product. If the fibres that have been dyed in the Vienna Textile Lab process are biodegradable, then this dye supports this end-of-life trajectory.

This material and process innovation shows a beautiful pathway for alternatives to fossil-based resources in the dyeing and finishing process. It can be a starting point for a model that involves local systems, given that the feedstock could be sourced from local waste and used in decentralised bacterial dyeing facilities on a range of fibres depending on the intended use.