Olympus Sashiko Kogin Thread - 100% cotton floss.  18m/ 19.8 yards per skein.

If you're looking for a thicker sashiko thread, you'll want to try Kogin sashiko thread.  Kogin sashiko thread is made of six fine stands of soft cotton.  Use all six strands together for a nice thick sashiko look.  The strands can be divided to use smaller amounts of the stands for other embroidery projects.