I thought a few other fibres might be of interest - they get everywhere and it can be good to identify the odd stray object. They also make interesting subjects for polarised light images:
Alpaca cloth, Zeiss plan 10/0.22, polarised light
Raw silk (note twin fibre with longitudinal striations) - Leitz 40/0.7 ICT (DIC).
Untreated jute - note bundles of fibres, Leica 20/0.3 EF L, polarised light
Jute fibres separated by heating with nitric acid/hydrogen peroxide, Leica 20/0.3 EF L, polarised light
Hemp, , Leica 20/0.3 EF L, polarised light
Flax (from linen), Leica 20/0.3 EF L, polarised light
Jute, flax and hemp are prepared from raw plant material by "retting" - soaking in water to soften the unwanted plant material so that it can be separated from the useful fibres by beating. This gives marked transverse striations, particularly noticeable with flax and hemp. Jute consists of bundles of heavily lignified fibres (can be stained red with phloroglucinol/HCl). These can be separated by heating with nitric acid/hydrogen peroxide.
All images were stacked and taken using a Zeiss Standard microscope. Polarised light images used a piece of plastic as retarder.
