From: Scott Wainer (smwbmp@starpower.net)
Date: 10/05/03-06:39:06 PM Z
Re: Fresson ProcessBecause of the number of people requesting information on this process, I am posting its description to the list rather than tie my computer up sending so many e-mails. Also, due to the length of the article I will break it up into 3 parts.
Please note that the formatting (and possibly spelling) was slightly changed from the original text by my OCR program.
From:
Handbook of Photography
Keith Henney and Beverley Dudley
1939, New York and London,
Whittelsey House division of The McGraw-Hill Book Co.
The SensitizerThis is normally a 1 per cent solution of potassium bichromate, made up as follows:
Water 1000.0 cc. 30 oz.
Potassium bichromate 10.0 g. 144 gr.
This keeps indefinately if protected from light and may be used repeatedly.
Different strengths of sensitizer may be used for different purposes, as will be discussed under Variations in Contrast.
Sensitizing
The potassium bichromate solution is poured into a clean tray to a depth of 1/2 in. or more, and the sheet of Fresson paper is slid into it, the edges being pressed down as they curl up, and any adhering air bubbles being broken by a light touch of the fingertip or of a softbrush, and the tray being rocked. At the expiration of 4 min. from the first immersion, the paper is lifted from the sensitizer and is hung up to dry in the dark; clips are used at the corners. It is advisable to hang it cornerwise, so that the sensitizer will drain from one corner.
Sensitizing may be done in any ordinary room, as the paper is not sensitive until dry; it should, however, be dried in the dark, sinse when dry it is slightly more sensitive than printing-out paper.
The sensitized paper will dry, in proper conditions of humidity, in a very short time - drying may be hastened by an electric fan - and the paper should be used as soon as possible, since when dry it tends to become insoluble without exposure to light. Even if kept in a sealed tin with preservative, as is done with platinum paper, it will not keep in good condition for more than a few days.
The sensitizer should be used at a temperature of between 65 and 75F.; if too warm it will soften the gelatin of the paper excessively.
If the paper is allowed to become bone dry while hanging up, it will curl very badly. It is therefore advisable to take it down when it is dry enough not to stick to anything and then to finish drying under light pressure. This is not, however, absolutely necessary, as with care, the paper can be handled even when badly curled.
Printing
This requires a strong light, such as is used for platinum or carbon, and no precise directions can be given as to time, as this varies with the negative, the color of the tissue, the possible moisture content of the colloid film, and the effect desired. Gennerally speaking, the cooler colors print more rapidly than the warm ones, and a bone-dry paper will print more rapidly than one which is faintly damp. Using the black paper, working with it bone dry, and working for normal results, the writer makes tests on P O P, then prints the Fresson for about three-quarters of this proofing time.
Developing
The print should be developed immediately after taking from the printing frame, since there is the same continuing action with Fresson that there is with carbon and gum.
To develop, the print is immersed for 4 min. in water at room temperature, then for 1 min. in water at 88F. It is then laid face up on a smooth slanting surface, and the sawdust soup is poured repeatedly over it. A convenient arrangement for thisapparatus was designed and made of sheet zinc by W. G. Houskeeper. It consists of a semicylindrical trough anout 18 in. long and 5 in. in diameter, supporting a sheet of zinc which has had the edges bent so that the soup will not run off them. The frough has feet to keep it upright, the sheet has a lip which projects slightly over the edge of the trough, and the upper end of the sheet is supported by a piece of 2- by 4- in. wood. An enameled cup from the 5-and-10- cent store is used for pouring. The exact angle of the support is of no great consequence. So long as there is slant enough for the soup to run off freely, it is all right - an angle of 30 degrees with the horizontal is satisfactory.
Development is continued until it has reached the proper point, when the print is rinsed with cold water to remove any adhering bits of sawdust and to set the gelatin. It is then hung up to dry; no further fixing or washing is necessary. The print will dry somewhat darker than it appears while wet - this darkening is more apparent in the shadows than in the high lights, so development should be continued until the print seems a little lighter than it should be when finished.
If for any reason it is not desired to develop the print at once, the continuing action may be arrested by washing the undeveloped print in six or more changes of water to remove the sensitizer. It may then be dryed and developed in the usual manner at any subsequent time.
Unless printing has been so deep as to require the use of water at 96F., it will probably be found that the margins of the print, even though masked in printing, will not develop clear but will retain more or less of the pigmented gelatin. Apparently a slight amount of light action is necessary if absolutely pure whites are to be secured. This residual is often very pleasing but may be removed with a brush if it is not desired.
For any given temperature, the print will develop to a certin depth, after which continued pouring of the soup has no effect. If it does not develop far enough after soaking at 88F., the print may be placed for 1 min. into water at a slightly higher temperature, after which development is resumed in the usual manner. It is not advisable, however, to go above 94 to 96F., since at this temperature the pigmented film will probably strip entirely from the paper, and even if it does not do this, the high lights of the picture will probably flake off, leaving blank spaces. If 96F. will not bring the print up to the proper point, it is seriously overprinted and should usually be thrown away, though it may sometimes be salvaged by brushing with a soft brush. This treatment, however, is likely to result in unsightly scratches on the surface of the print.
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