Alice Klein in New Scientist:
Spider silk has been eyed as a greener alternative to synthetic fibres, which are derived from fossil fuels and leach harmful microplastics into the environment. Farming silk from spiders themselves is difficult, however, because they tend to eat each other and only produce a small amount of silk fibre to make their webs. A 4-square-metre spider silk shawl that was displayed at the Victoria and Albert Museum in London, for example, had to be created from the silk of over 1 million golden orb-weaver spiders.
As a result, several groups have tried to genetically engineer silkworms so that they make spider silk instead of their own silk, since silkworms are easier to farm and spin much larger quantities of fibre. But until now, the silk produced by these modified silkworms has been less than 36 per cent spider silk.
More here.