Every quilter needs this 12 Wt. Solid Cotton Quilter's Assortment! Sulky Cotton Thread is made from premier quality, long staple, highly mercerized, 100% Egyptian-grown cotton. Sulky's 12 wt. Cotton Thread is 40% thicker than 30 wt.  You will love these 10 spools, which were carefully chosen for all your quilting needs.