Chemical and Engineering News, 1999
The “pill,” as it’s called, is machine-wound under high, consistent tension with 121 yards of four-ply blue-gray wool yarn, 45 yards of three-ply white wool yarn, 53 more yards of three-ply wool yarn--this time blue-gray in color to denote the stage of manufacture, according to Rawlings--
and 150 yards of fine white polyester-cotton blend yarn. This “center” is coated with rubber cement before the cover is put on.

The cover--two pieces of elongated figure-eight-shaped white cowhide--is dampened to permit stretching and hand-stitched together with exactly 216 raised stitches, using 88 inches of red cotton thread. The last step in the process is rolling the balls for 15 seconds while still slightly damp so the seams are even and reasonably flat.