The plot of causing two cards to fuse into one was published by Norm Houghton as “Stranger of Another Color” in Ibidem, No. 5, Apr. 1956, p. 19. Houghton had a blue-backed card fuse to the face of a red-backed selection. No signatures were involved.
Several years later, signatures made their way into the fold. The first few handlings to involve signatures weren't presented as fusions, but rather as predictions or moveable ink – the result was the same, though; that of two signed cards becoming one. The first of these was J. G. Thompson, Jr.'s “Joint Signature” from The Pallbearers Review, Vol. 5 No. 12, Oct. 1970, p. 365. In this trick, a prediction card, signed by the performer on the back, ends up on a selection signed by its chooser on the face. The next was Karl Fulves's “Future Minus” from The Book of Numbers, 1971, p. 39. A red-backed prediction card fused to the initialed face of a blue-backed selection. Dan Tong later used signatures to reintroduce the fusion premise with “Signature” in The Blueprint, Vol. 1 No. 8, Feb. 1975, p. 32. Ian Baxter – an editor of The Blueprint – anachronistically published his own variants of Tong's trick as “Signature Variations” in the previous month's issue, Vol. 1 No. 7, Jan. 1975, p. 27.
Wesley James has claimed the Fusion plot as his, but he didn't publish his “Forgery” until Stop Fooling Us!, 1989, p. 39. James has two cards fuse, one signed by the spectator, the other by the performer. Even if calculating by James's claims of creating his trick in 1965 (see Enchantments, 2004, p. 5), Houghton's fusion effect, although lacking signatures, predates it by nine years.
The open use of gimmicked cards was later introduced to enhance the effect. Gene Maze, Richard Kaufman, and David Arthur used a double-backed card in their “Fusion” routine from CardWorks, 1981, p. 47. Strictly speaking, this wasn’t a fusion routine, regardless of the title. The cards weren’t fused but merely “stuck together” (which, while similar, is conceptually different). The double-backer was then split back into two cards, giving the merger no permanency. That same year, Paul Harris and Looy Simonoff published “The Beast with Two Backs” in Close-Up Fantasies Finalé, 1981, p. 113, which ended with two cards permanently fused together in the form of a red/blue double-backer. Steve Beam developed the idea of ending with a double-facer, publishing it as “Making Faces” in The Trapdoor, No. 7, Jan. 1985, p. 115. In his text, Beam claims to have been doing the routine since his college days.
Prior to the fusion effect being applied to cards, it was suggested for coins and billiard balls.