Oil printing #2 ("Hopping" and "Dabbing")
from "The Photographic News Year-Book of Photography and Amateurs' Guide," 1907-8 (I don't know where this falling-apart book came from, the price is on the cover in British money, and the cover falleth off... more I cannot say.)
Rawlins' Oil-Pigment Process
To prepare paper for use, immerse each piece in potassium bichromate, 1 oz, water 20 oz.
Soak well for about 1 minute, removing any airbells. Remove paper, drain, and hang in dark to dry. It's most convenient to sensitise the night before, as complete drying takes several hours. The sensitized paper will keep a few days, but is best used fresh.
Print by daylight in the usual manner [presumably under a negative: it doesn't say, and of course not everybody had electricity in 1907]. Being very careful not to overprint: the paper requires only about 1/8th the exposure of POP. The image is just visible and should be printed out (exposed???) until the faintest detail appears in the highlights.
Remove from printing frame & wash in cold water til yellow bichromate stain is gone, which takes 20-30 min.
Place print face up on pad of clean blotting paper previously saturated with water. (Pad may consist of several thicknesses of ordinary blotting paper, supported on a flat surface, such as a piece of glass.) Blot off the superfluous moture from the surface, being careful not to extract the moisture from the gelatin coating itslef. Now spread a little of the prepared pigment on a palette (eg. a piece of clean glass), very thinly & evenly. The special brush is then applied gently 3 or 4 times to the patch of pigment until it is lightly chrged with pigment.
Application of the pigment: Two possible ways, hopping or dabbing. The hopping means holding the brush vertically about 2 inches away from the surface of the print, letting it drop & catching it again as it bounces. This method is most suitable for light delicate sujects, without any large dark areas. At first the pigment will adhere only slightly, but gradually the image will develop, building up. The brush needs frequent replenishing with pigment, especially at first, but when the picture is nearly done, this isn't necessary.
For heavier subjects it's better to dab the pigment more or less all over the print at first (except for a face or highlights, which should be developed by "hopping") and complete the print by hopping.
Hopping & dabbing can be alternated, and varied according to conditions and desired effects. Remember that hopping tends to produce contrast, dabbing gives heaviness & flatness.
By varying the manner of applying the brush all kinds of effects are possible, much control is also possible. Hopping with a brush fairly free of pigment takes off color, and lightens distance or clears highlights. Dabbing with a full brush puts in color & deepens shadows, or hides unsightly features of the composition. Any part of the picture may thus be manipulated according to the taste and feeling of the worker & without affecting the other parts. Or perectly straight prints are equally easy.
However, if pigmenting is extended for too long, the coating may lose its moisutre by evaporation, making it hard to bring out contrast. In this event, slip the print, face up, under the surface of water in a deep dish for 5 or 10 minutes.
When the picture is finished, pin it up to dry. Whch may take a few hours to a day or so before "tackiness" quie disappears. As soon is it's fairly hard, bits of hair or fluff may be removed, usually possible by rubbing with a dry cloth, or using a needle or sharp point of a knife to remove hairs.
I have one more overall description from Neblette, very simple and IN ENGLISH... which I'll do approximately tomorrow.