Stella McCartney Brand Book

SUSTAINABILITY
Bolt Threads Mushroom Leather.
MUSHROOM LEATHER
MYLO
In 2018, Stella McCartney and Bolt Threads unveiled a new
bio-material grown from mycelium, an underground root
structure. The first of their products to be created out of the
Mylo material was the iconic Falabella bag which was exhibited
at the Victoria & Albert’s Museum in London. The material
is still in the research and development stage but a large-scale
commercial roll-out is expected.
Mylo looks and feels like hand-crafted leather. It has a soft,
supple, natural feel, and every sheet yields unique variations
in thickness, making each product one-of-a-kind.
Mycelium is composed of billions of cells which form a 3D
mesh on a micro-scale. It forms vast networks of threads that
help recycle organic matter on the forest floor while providing
nutrients to plants and trees. The threads interweave and
self-assemble into a 3D matrix that can spread for miles. It is
vital to our ecosystem and infinitely renewable, which makes
it ideal ingredient for an innovative material like Mylo
This leather-like material is made by combining mycelium cells
with a substrate of corn stalks and nutrients. Over 10 days the
cells grow into the substrate, creating an interconnected mass
that can be made into almost any size. The quality of the resulting
material depends on factors such as environment, nutrients
and how it is tanned. Stella McCartney avoids the use of toxic
chemicals in the dying of Mylo material.
The sustainable material looks and feels like animal leather,
is supple but also strong and abrasive resistant. It grows in a
matter of weeks, compared to animal hide which takes year.
It also has better moisture management than leather. Because
Mylo is made from organic matter, it is completely biodegradable
and non-toxic.
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