UJ Cotton Use Vintage, Replicated Classic Model Jeans stitching thread Cotton piece-dyed sewing thread Characteristics UJ 100% supima Cotton sewing thread, it is possible to make items where the color will remain, even after numerous washes or through chemical treatment of the jeans in the washing process. Even after numerous washes, the color on this cotton thread will not become soiled when compared to polyester threads. Up until 1960, UJ cotton #ZX-1, ZX-2, and ZX-3 was produced to resemble handmade, cotton sewing thread. And at the time, the color on these threads gradually faded to yellow during the washing process.This created a very unique characteristic that is no longer found in threads today. However, we continue to make these sewing threads in the same traditional way retainin it is unique characteristics. We also can produce this in the original #0 count size that was prevalent back then than no longer exists now.C/#BW is for piece-dyed and white denim products. Colors BW dyes at the same rate as the offwhite cloth into any color ranging from extremely light colors to dark colors.This 100% Cotton sewing thread retains the excellent features of the raw material. quality cotton100% construction #0/770 20s/3x3 (2655dtx) #6/2000 30s/1x9 (1770dtx) #8/3000 30s/2x3 (1180dtx) #20/4000 40s/2x3 (855dtx) #30/5000 30s/1x3 (580dtx) #50/5000 50s/1x3 (380dtx) #50/10000 50s/1x3 (380dtx) Ujyo Bussan Co.,Ltd.