The effect of causing a miniature image of a selected (forced) card appear on a small piece of paper sandwiched between two large coins has become a well-worn classic. A clear predecessor is the “Spirit Photography Card Trick”. The trick as it is commonly done was originated in 1931 by Al Baker. A coin shell is cleverly used to switch the small piece of blank paper for another with a miniature card printed on it. However, Baker's main inspiration was a similar effect first marketed by A. W. Gamage.
Al Baker first advertised his trick as “The Coin and Card Trick” in The Sphinx, Vol. 30 No. 8, Oct. 1931, p. 384; and as “The Card and Two Coin Trick” in The Linking Ring, Vol. 11 No. 8, Oct. 1931, p. 847. Marketed through Baker and Sunshine's Broadway Magic Shop, the trick came with the necessary coins, shell, miniature cards and instruction sheet. In the last paragraph of the instructions, Baker acknowledges an earlier method. He writes:
“You will find the Al Baker method superior to the old fashioned way of having a point soldered to the face of shell coin. There is no point to bend or break or puncture holes in your cards in this up-to-date version.”
The existence of this earlier method is also implied in the full title on Baker's instruction sheet: “The Al Baker Method of Performing the Coin and Card Trick”. The method Baker referred to is one marketed by A. W. Gamage, Ltd. in 1911. Presumably, it was Gamage's invention, as it was titled “The 'A.W.G.' Card and Coin Effect” in the ads appearing in Will Goldston's The Magician Monthly. The first ad appeared in the Jan. 1911 issue, Vol. 2 No. 7, p. 22. The ad copy ran: “A selected Card is returned to the pack and shuffled. A Penny is placed on the table, then covered with the pack. Upon the person naming the chosen Cards [sic], the pack is removed, when a miniature duplicate of the card is seen on the penny. JUST OUT. CAN ONLY BE OBTAINED OF US.”
Roughly a year later, Goldston included an explanation of the trick in his The Young Conjurer, Part Two, 1912, maintaining its marketed title. In this early version, a blank piece of paper is not used. The shelled coin is employed simply to produce a miniature card. For this method, the shelled coin is covered with the deck instead of a second coin. The shell carries two tiny pinpoints on its face. When the deck is pressed down on the shelled coin, the shell is picked up, having impaled the bottom card or cards of the pack.
It was only a matter of time before magicians and magic dealers would realize that a temporary adhesive – “sticky stuff”, as Al Baker called it in his 1931 ad: “no hooks, pins or sticky stuff on coins” – could be substituted for pins, making the gimmick easier to make and less destructive to the cards.
However, Baker was more likely referring to a competing method being simultaneously sold in 1931 by Max Holden, and also advertised in the Oct. 1931 issue of The Sphinx, p. 397. Holden opens his ad with “So good others are trying to copy it.” This comment was probably directed at Baker. Holden's method is given in an instruction sheet titled "Max Holden's - Card on the Coin", issued by him. His effect more closely resembles Gamage's than Baker's version, with the miniature card being produced on a single coin covered by the deck, rather than being magically printed on a blank piece of paper between two coins, as Baker did it. Holden, though, reversed the previous method. Instead of stealing the shell from its coin, he added it and the miniature card to a previously examined coin. Holden used diachylon or wax to adhere the shell to the deck, and then disengaged it once the coin was nested inside the shell.
Barbara Walker, in her Miniature Mysteries with Cards (1980), gives an interesting chronology of the development of the trick and its variations (see pp. 42-48), although Al Baker's seminal contribution is overlooked.
In 1934, Baker renamed his version “The Photographic Coins” and bundled it with two other tricks using the same shell and coins. He sold this under the omnibus title of "Al Baker's Tri-Coin". In the instruction sheet supplied with this, the mention of earlier methods was dropped.
After reading a handling by Fred Braue of the Baker trick (see “Spirit Cartography” in Hugard's Magic Monthly, Vol. 6 No. 11, Apr. 1949, p. 531), Phil Goldstein developed a method that eliminated the use of a shell coin and varied the effect to spirit writing rather than a playing-card revelation; see “A Dollar” in The Chronicles, No. 9, 1978, p. 1148.