This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Caution. - Never dip the cotton stump in the turpentine while charged with colors - always make a new stump. Always use the same end of the wooden stick for the plain turpentine stumps, while the other end should be reserved exclusively for the colors. In applying the color to the face, be very careful that it does not spread over onto the background. Avoid working too close to the outlines of the face, as the color can be spread when shading and blending by rubbing with the cotton. It is important that the colors be applied and spread rapidly and evenly, and the rubbing continued until dry, for the turpentine quickly evaporates, the colors becoming quite permanent and somewhat difficult to alter.
Second Tint (Natural Red). - Charge a clean stump with the same colors as before, but without turpentine. Place the stump between the two fingers and turn toward you in a circular motion, so as to harden as well as sharpen the stump. This only requires from three to five seconds. When in proper condition begin on the prominent portions of the cheek, rubbing lightly and in a circular motion; then proceed in a similar way on the lips, ears, chin, etc. If the color is too yellow add a little crimson, and vice versa. Each time before applying the color see that it is set well into the stump. The application must be light, and then the color rubbed dry with a clean dry stump. Next, with a wad of cotton blend the colors together. In some cases it is best to blend the colors before applying the red to the lips, cheeks, ears and chin; but after applying the red these colors can be blended over the former blending.
Third Tint (Shading). - Add some burnt sienna to the flesh tint, and apply with the same stump, rubbing lightly and evenly. For dark shadows apply more pressure to the stump, and less for light ones. After all the shadows are colored rub with a clean stump, always beginning with the lighter portions and rubbing into the shadows so that the color is not carried from the dark to the light. No harm is done if the light color is carried into the dark parts. As previously stated, the face may look very well colored with three distinct tints, but four or five will materially improve the result.
Fourth Tint (Lights). - The lightest parts of the face or the figure should be built up with a small and finely-sharpened stump immersed in turpentine and then pressed between the fingers and a linen rag. Turn the stump constantly toward you until it becomes quite dry. Apply the stump lightly at first, and if too much color is removed a tuft of cotton may be used to blend in the surrounding tints. The turpentine must be applied to these high-lights in a circular motion, and before the outlines have had time to dry. Be sure to use a clean stump for this work. To give the high-lights a natural flesh tint they can be touched with a little chrome yellow. This is best applied with a soft, puffy stump, afterward rubbing the surface with a dry stump or wad of cotton. If too yellow it can be rubbed off with the dry stump, by simply applying a heavier pressure.
Fifth Tint (Semi-tone). - For the semi-tone take a little cobalt blue on the point of a small stump. Rub dry by placing the stump between the finger and the linen rag, and then apply very lightly to the surface between the lights and shadows. Rub close to the hair, under the eye and the lips, on the chin, etc. After the semi-tone is applied go over all the surface with a dry stump until the tone is evenly blended and the colors have become quite dry.
The Eyes. - Wash the eyes with turpentine, using a fine stump, and then color the white portions a light blue. When rubbed dry the iris should be painted with whatever color is desired. This is done with a stump that has not been moistened with turpentine, as previously explained. For the pupil, use black on a dry stump, roll the stump to a very fine point, between the finger and cotton cloth, until it becomes quite dry. Then use this as a pencil and apply the color with the tip. This stump is also used to retouch the eyebrows and lashes.
Outlining the Face. - After completing the coloring of the eyes the face can be shaded in strong, bold lines, by using crimson and burnt sienna - for instance, under the eyelashes, in the corners of the eye, on the lips, under the chin, in the ears, etc. If you find, after applying these colors, that the shade is too dark, remove it with a dry stump. This retouching of the outlines gives the portrait a more clean and artistic appearance.
Coloring the Hair. - If the hair has been touched with any other color, it should first be washed with the turpentine applied with the stump, and then rubbed over with clean cotton, after which color to any desired tint. When coloring the hair be careful not to touch the face. It is best not to color quite to the outline of the hair, for the tint can be easily spread by rubbing. The basic color is always put on with a stump moistened with turpentine; for shadows no turpentine is used; while lights are put in with turpentine only. For mixing colors for hair, see previous instruction.
Coloring the Drapery. - In coloring the drapery proceed exactly the same as with the other portions, beginning with the foundation tint, first covering the main surface, then the shades and shadows in their proper order, and finally the high-lights. In applying the colors to the drapery, be sure that they are not too thick. For working up the pattern or figure of the goods, also the shadows of the drapery, with the final shades, use the color without turpentine, and blend with the tuft of cotton. See Drapery Color Mixture.
Coloring Lace and Jewelry. - Jewelry must first be colored with the foundation tint, followed with the shades. The lights can be produced with turpentine on a small stump, or with an india rubber. If a very fine high-light is desired use the point of a sharp pen-knife, or lay on thick Chinese white. The former is preferable. Seven colors are quite sufficient for any desired effect, for with these many additional colors may be made. Of course, after longer practice more colors may be used.
Varnish. - To produce a glaze surface like that of an oil painting, cover the picture with varnish. This may be done by preparing a mixture of one-fourth varnish and three-fourths alcohol. Spray this solution over the print with a blow-pipe, or with an air-brush. When using the blow-pipe, hold the print at arm's length; and placing the blow-pipe in the tumbler of prepared varnish, blow through the tube toward the print. This gives an even, fine spray. Continue the varnishing until the entire print is thoroughly sprayed. If too much varnish is applied the print will be too glossy. An excess of alcohol will produce tear drops. Where these exist add more varnish, which will remove the tear drops. While any varnish used by artists will answer, Soehnee Freres is always reliable.
Retouching Prints with Oil Colors. - There are times when it is quite difficult to spot photographs with the ordinary brush and obtain the proper blending of color, whether the print is water color or black and white. This may be accomplished with the oil colors. For the retouching of white spots a very fine stump is necessary. Charge the stump with the required color and rub dry between the thumb and a soft cloth, laying the cloth over the index finger. Constantly turn the stick toward you until the grease has disappeared and the oil becomes quite dry. Touch the spots as lightly or as heavily as is necessary to fully cover the spot; then with a little absorbent cotton blend the color of the main surface of the print, when the spot will be entirely removed and the spotting will not show. Spotting of both sepia and black and white platinum prints is very successfully handled with the oil colors.