Rare and quite choice vintage black fountain pen signature, adding Betty Boop's signature line "Boop boop a doo," on a 3x5-inch tan card, part of a large collection of autographs acquired on cards in-person in the 1930s. In good condition, with toning where four photo mounts had once affixed the card to an album page. Excellent for matting with a favorite photograph. Adorable, squeaky-voiced singing and occasional film star Helen Kane made wildly popular records of "Get Out and Get Under the Moon" (1928), "That's My Weakness Now" (1928), "I Wanna Be Loved By You" (1928), "Is There Anything Wrong with That?" (1928), "Don't Be Like That" (1928), "Me and the Man in the Moon" (1928), "Button Up Your Overcoat" (1929), "Do Something" (1929), "I'd Do Anything for You" (1929), "He's So Unusual" (1929), "Aint'cha?" (1929), and "Dangerous Nan McGrew" (1930). Mae Questel's dead-on impersonation of Kane was used by Max Fleischer Studios as the voice for Betty Boop in 1930s, as was her euphemism for lovemaking, "boop-boop-a-do."