| gornyhuy |
09-29-2004 10:27 AM |
Beginning in 1910, Ditto, Inc., sold gelatin duplicators that were essentially large mechanical versions of the Daus Tip-Top Duplicator pictured to the right. Like the hektograph, the Ditto process could be used for up to 100 copies. Plate 34A is a 1925 Ditto machine. "When preparing the original, hard bond paper and a special kind of ink [containing aniline dyes] are used. This may be in the form of a duplicating typewriter ribbon, a duplicating ink, or even an indelible pencil. The original is placed face down on the copying surface and smoothed with the palm of the hand or a roller. It is then lifted off, having left its impression on the gelatin. The blank sheets are placed one at a time on the gelatin surface and allowed to remain a few seconds until the imprint is made." The Ditto machine in Plate 34A was $200. In 1925, other models were $117 to $395.
The spirit duplicator, which was introduced in 1923 and which was widely used for several decades, evolved from the hektograph and Ditto machines described above. The best-known spirit duplicator company was Ditto, Inc. The Ditto process involved the creation of masters and the transfer of ink from masters to copies. A Ditto carbon consisted of a sheet of slick, impermeable paper (the master) attached to the front of a second sheet that had on its face a coating of paste-like ink. When one typed or drew on the front of the master, a reverse image in heavy ink was transferred to the back side of the master. The master was then detached from the second sheet and attached to the drum of a rotary press with the inked surface outward. When the drum was rotated, the inked surface of the master was wiped with a solvent such as spirit ether to wet the ink, and until the ink was exhausted impressions were made on papers that were fed under the drum.
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