I recently found these two wonderful books on shifu, paper thread making and paper thread weaving. The first book Kigami and Kami-ito is beautifully laid out and the images are inspiring. A Song Of Praise For Shifu is exceptionally full of information about paper making, as well as, the regional variations and history of shifu.
I have been collecting antique daifukucho, or account books. Some of these daifukucho date to the 1840’s and were used by a lumber company, but most of them date to the 1880’s and 1890’s. In the past it was common for these books to be taken apart and the strong kozo paper cut up to make paper thread which would be used as weft threads on a hemp or cotton warp. I bought many of these thinking that I might try my hand at making shifu using antique paper, but each page is like a work of art and I don’t know if I can ever bring myself to use them. You can purchase late 19th century daifukucho through my shop at https://www.etsy.com/shop/luckyredbat?ref=hdr_shop_menu
I recently ordered some beautiful hand made kozo paper and tried making kami-ito, paper thread using the books on kami-ito and shifu I mentioned above. I cut the kozo paper into thin strips leaving both ends attached, then I left the paper strips under a damp towel overnight, in the morning I rolled the moist paper on concrete blocks, and then spun the thread using a Japanese spinning wheel.