Here are 35 Famous Cartoonists Series Buttons from the series of 54 created in 1975:

#1 Sergio Aragones, #2 Bob Armstrong, #5 Joel Beck, #6 Fershid Bharucha, #7 Tim Boxell, #8 Sol Brodsky, #9 Leslie Cabarga, #11 Dan Clyne, #12 Richard Corben, #14 Howard Cruse, #18 Vincent Fago, #21 Justin Green, #22 Bill Griffith, #23 Hugh Hefner, #24 Fred Julsing, #25 Jay Kinney, #26 Denis Kitchen, #27 Aline Kominsky, #29 Peter Loft, #31 Jim Mitchell, #32 Willy Murphy, #33 G. Natwick, Boop, #34 Peter Poplaski, #35 John Pound, #36 Ted Richards, #37 Trina Robbins, #38 Spain Rodriguez, #39 Sharon Rudahl, #40 Bill Sanders, #42 John Severin, #44 Barry Smith, #45 Art Spiegelman, #47 Steve Stiles, #49 Mort Walker, and #50 Skip Williamson.

All the color buttons are 2.25 inches in diameter, metal with clear celluloid covers, and have "safety" pinbacks.

From Denis Kitchen:

Pinback Jack issued this "Famous Cartoonist Series" of self-portrait buttons back in 1975. All of the participating cartoonists were alive and created self-portraits specifically for this button set. With very few exceptions, the images have not appeared elsewhere in print. The buttons were distributed by Krupp Comic Works and Phil Seuling.