From  Superior Threads
In King Tut 40wt 500yd = 12101 
DESCRIPTION
King Tut is one of nature's finest threads. It is certified Egyptian grown, extra-long staple cotton and designed for quilting on both home and machines and longarm machines. King Tut thread is 3-ply 40wt thread made for quilting. 

With the finest spinning, twisting, dyeing and finishing techniques, King Tut has extremely low lint. You and your machine will thoroughly enjoy the quilting experience.