Bowling has letters on bowling pins. On the upper-case keys, the bowling pins are white with black letters and on the lower-case keys the pins are black with white letters. The lower-case letters can be colored and placed behind the upper-case letters to give two-color lettering. (The letters on the pins are from the typeface InsideLetters.)

A set of plastic pin-back letters served as the model for Monthly Meeting JNL. Pin-back letters were primarily used on cork bulletin boards for changeable notices and announcements.