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.
Method Of Procedure. To execute the developing method of vignetting, place the sensitive paper on the negative in the printing frame in the regular way; hold the frame up to a yellow light so you can see through the paper from the back. With a soft pencil outline on the back of the paper the parts of the view you wish to show. By holding the glass and print before the yellow light, you will be able to locate the part you have outlined with the pencil. Next place the paper back on the printing frame and expose the entire negative to the light just as though you wanted all of the print to show. Next wet a piece of glass, a trifle larger than your print, placing the undeveloped print on it face up. The wet glass will prevent the print from curling or sliding. You may hold the glass containing the undeveloped print in the hand, or place it on a table. With a tuft of absorbent cotton, which has been previously dipped in the developer, carefully swab the parts to be developed, always beginning in the center of a print, working slowly until the image begins to appear. Continue the swabbing as far as desired. As you near the point where it is intended to stop development, work more lightly. In this way a soft blending into the background can be produced.
807. Another method of obtaining vignettes by development is accomplished by the use of glycerine or a solution of sugar, this latter being obtained by boiling crystal sugar until it becomes gummy and then straining it through fine muslin. With this method, truer vignettes can be obtained than when the developer is applied direct to the paper. It is advisable to have a fully developed print at hand, as a guide by which to vignette the print. Take a sheet of glass, coat it with glycerine or the sugar solution and lay the print on it, face up, being careful to observe which way it is taken from the negative so as to be able to locate the highlights with the aid of the guide print. The glycerine will hold the print down without curling. Next, mix one part glycerine or sugar solution with three parts developer and then apply, with camel's hair brushes or a tuft of cotton, the mixture to the print, first laying it on the highlight portions, then on the half-tones, and finally on the shadows, always beginning to work in the center of the print. In this way, over dense shadows can be restrained. Gradually work out toward the edges of the print, leaving these parts until almost all of the print which is desired has gained its full strength. The gylcerine will so retard the action of the developer that it will leave a perfectly vignetted edge, those parts of the print untouched with developer clearing up a pure white in the hypo bath. The sugar solution used as a retarder will tend to preserve the rich black tones of the print, while glycerine will frequently give brownish tones, which are, however, by no means displeasing.
808. Care must be exercised regarding temperature of the developer. Never use a warm or a badly discolored developer. Use fresh cold developer. Warm developer will cause the image to oxidize very quickly leaving a yellow or brown outline to the vignette. When sufficiently developed, place in your acid clearing bath for a few seconds and then transfer to your regular acid hypo bath.
809. First results will probably not be satisfactory, as it requires a little practice to produce soft blended effects in the vignette. After fixing, should the vignette appear quite harsh; the outline too sharp; printed parts leaving off too abruptly; they can be blended by applying, with a tuft of cotton, a strong solution of chloride of lime. After softening down the vignette, dip the print in fresh water and return to the hypo for ten minutes. This is necessary, because any part of the print which has been removed with the chloride of lime is apt to redevelop and appear again, unless fixed in the hypo.