These pirns are wound with silk yarn. The silk yarns are either: doupioni silk (a slubby silk yarn with bumps and irregularities where the fibers from several cocoons have been reeled together), tram silk (a slightly twisted yarn made from several strands of reeled silk) or spun silk (2 strands of tram have been plied together to make a tightly twisted yarn). The Large pirns contain approximately 1.5 oz of silk on each pirn, and small pirns contain approximately 1 oz of silk on each pirn. The amounts on the pirns varies.
The yardage on this silk yarn is approximately 14,000 yards per pound.
The pirns are from the last silk mill in the US to make silk ties and bridal fabric. The wooden pirns are from the silk mill. The do not fit new end-delivery shuttles, you will need to wind the yarn onto your own shuttle prior to use in weaving.