https://trc-images.nl/collection_images/hires/2016/2016.2279d.JPG#\\TRC-SERVER\TRCSharedWork\TRC Database\collection%20photographs\2016.2200\2016.2279d.JPG#
A warp thread made of New Zealand flax (Phormium tenax).
In New Zealand flax was traditionally used to make a wide variety of objects including baskets and skirts.