Identifier: americanannualof3334newy (find matches)
Title: The American annual of photography
Year: 1919 (1910s)
Authors:
Subjects: Photography
Publisher: New York : Tennant and Ward
Contributing Library: Harold B. Lee Library
Digitizing Sponsor: Brigham Young University

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ront from the back when it is wet, and shouldbe put to soak in cold water for half an hour—more can do noharm—care being taken to see that no bubbles adhere to it,and that the coated side is kept immersed. If a very roughpaper is used, it is well to give it five minutes in water at140° F. immediately before transferring. Transferring should be effected at once after printing, toprevent what is known as the continuing action. Thisphenomenon, observable in the case of bichromated colloids,means simply that such a colloid, exposed to light, will con-tinue to print after being removed from the light, even thoughkept in absolute darkness. Thus, a carbon print, printed toone-third the proper depth and placed in a dark closet, willprint to full depth in a few hours, or if correctly printed in thefirst place, will be totally ruined by the continuing action. Thiscontinuing action may be retarded by keeping the print underpressure—as in a printing-frame—by keeping it absolutely dry 194
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w CO DO <u HQ U l-H < XH O CO QO 195 —as in a platinum tin with preservative—or may be complete-ly arrested by washing the print thoroughly in cold water,afterward drying it. The writer has printed a piece of carbontissue to the correct depth, washed it, and transferred it twoweeks later, with perfect success, but this is not advised, it be-ing better to transfer as soon as printing is complete. The transfer paper having been soaked and the tissue print-ed, the former is placed face down in a tray of cold water andthe latter is placed face up in the same tray, air bubbles beingremoved. The tissue will at first show a decided tendency tocurl up, face inward, and must be prevented from doing so bythe fingers. After a few seconds immersion, it will flattenout, and if left long enough would curl the other way, as thegelatine gradually absorbs water. However, just before thetissue becomes flat the transfer paper is turned face up and thetissue face down, the two being lightly pre

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