Ink traps

Ink traps are a feature of certain typefaces, most notably Bell Centennial, where corners or details of the letterforms are removed, usually at a junction, to compensate for the spread of ink during printing on newsprint. Bell Centennial was designed by Matthew Carter for AT&T, who required a new phone directory typeface (for their 100th anniversary) that would fit more characters per line and increase legibility at a smaller point size. Carter improved on AT&T’s earlier typeface, Bell Gothic, by increasing x-height, slightly condensing character width, opening up counters and bowls, and drawing deep ink traps, which, at the smaller point size used in the phone book, become invisible.