James C. Sternberg' Michigan State Universify East Lansing
Rapid Preparation of Lantern Slides
It is frequently difficult or impossible to plan lantern slides sufficiently in advance of their use to have photographic slides prepared. Lantern slides prepared by typing on paper or by use of various commercially available slide materials frequently lack the desirable sharpness of definition. A new method which has been found to give highly satisfactory slides is the direct transfer of the surface of a "DittoH*carbon sheet to a glass slide. The content of the slide is first laid out on a sheet of tracing paper in just the way it is to appear on the slide. A lantern slide cover glass is then placed in proper position under the tracing paper, and a "Ditto" carbon sheet (or a piece cut from one) is inserted between the tracing and the glass, with the waxy transfer surface toward the
* "Ditto" carbon sheets are supplied by "Ditto," Ino., for use in preparing master sheets for fluid duplicator machines. Best results have been obtained through use of red carbons. 1 Present address: BeckmanInstruments, Fullerton, California.
glass. The proper juxtaposition can be stabilized by judicious use of masking tape. The content of the slide is then traced directly on the tracing paper, using a ball point pen or a sharp (medium to hard) pencil, transferring the information from the "Ditto" carbon to the glass; only a little practice is required to find the optimum pressure. Errors can be corrected by erasure from the slide with a razor blade. To insert the correction, a small fresh piece of "Ditto" carbon must be inserted in the proper place. The slide can be used directly as a single piece of glass, or it may be protected against smearing by covering the printed side with a clear slide cover glass and binding the pair as a normal slide. The waxy lettering gives sharp, clear images upon projection and shows no tendency to wilt upon prolonged exposure to the heat and light of the projector. The glass can be cleaned with aqueous detergent or with organic solvents so that the glass can be re-used when the slide is no longer needed.
Volume 37, Number 2, February 1960
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