. The book of photography; practical, theoretical and applied. slight. Thenegative must be a bright black and whiteone, on Avet collodion or photo-mechanicaldrj plates, and free from flaws orscratches. Printing may either be ex-amined during progress, or judged byactinometer. The next proceeding is theinking-up, which should be done in aroom of even temperature. For this pur-pose transfer ink is used, the ink beingw-ell distributed over a stone ink slabwith a lithographic leather roller, a velvetroller (Fig. 891) being then employed totake up sufficient ink from the slab. Iftoo stiff, the ink
. The book of photography; practical, theoretical and applied. slight. Thenegative must be a bright black and whiteone, on Avet collodion or photo-mechanicaldrj plates, and free from flaws orscratches. Printing may either be ex-amined during progress, or judged byactinometer. The next proceeding is theinking-up, which should be done in aroom of even temperature. For this pur-pose transfer ink is used, the ink beingw-ell distributed over a stone ink slabwith a lithographic leather roller, a velvetroller (Fig. 891) being then employed totake up sufficient ink from the slab. Iftoo stiff, the ink is thinned with a littlepoppy or almond oil, thoroughly mixingwith a palette knife before using ; if toothin, some stiff lithographic ink must beadded. The dry print is roiled witli thevelvet roller until it appears of an evenlight grey tint; it is then placed in coldwater. Another method of inking-up isto thin the transfer ink with benzole andturpentine, applying the mixture with atuft of cotton-wool, or the leather rolleralone may be employed. An inking-up. Fig. 892.—IXKI\G-UP not come away easily, the print is re-turned to the water for a longer immer-sion. When development is finished, theprints are pinned to a flat board andallowed to dry, or placed in a drying ovenas previously described. For half-tonetransfers a tuft of cotton is preferable toa sponge for removing surplus ink. Transferring to Stone. This is done as in the ordinary methodof lithographic printing. The print iswetted by placing it in a damping book,the film side being covered with thin,smooth paper. The transfer is then laidon the stone, a sheet of cardboard beingplaced over it, and on that a perfectlysmooth sheet of thin zinc. The stone,transfer, etc., are then passed through thepress, at first with but little pressure,v. hich is afterwards increased if paper is then removed, and shouldleave the whole of the ink on the the paper shows any reluctance to PHOTO-MECHANICAL PROC
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectphotography, bookyear
