How it works. The cap is a 1.6 mm shell around the ball with a third of a millimetre to spare, cut off two thirds of the way down so it drops on and lifts off; the two ears hold it still against the ball. The letters and the line are cut straight through the top, where the ball is nearly flat under them, so a marker follows them cleanly. Letters with centres — A, B, D, O, P, R, 0, 4, 6, 8, 9 — keep the centre on a bridge, so nothing falls out.
Printing. One piece, rim down, no supports. A regulation 1.68" golf ball or a 74 mm pickleball; the pickleball's letters are bigger to match.