| Gordon Chapple |
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| Carbon Transfer Photographs |
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Photographic Equipment All of the images have been made with an 11x14 Phillips Explorer camera on a Ries tripod and Ilford HP5+ film. I use a combination of lenses with this camera: 250mm Wide Field Ektar, 14" Schneider Gold Dot Dagor and 24" Red Dot Artar. Film Development Most all of the negatives have been developed in PMK Pyro. Some of my earlier work was processed in D-76. In all cases, development is done using a nitrogen burst processing system. While I use the zone system for exposing the film, I process the film for much more contrast then one would normally desire for gelatin silver printing. Darkroom Equipment The hardware used to make carbon transfer prints is very different from conventional darkroom equipment. Enlargers cannot be used with this process, as the images must be contact printed using a high intensity ultra violet light source. The key equipment in my darkroom is a NuArc 1000 watt plateburner and a Stoesser registration punch, which is critical for maintaining registration when I overprint the image. Tissue Production and Printing I make two different colors of tissues: pearlescent silver and warm black. The pigment sources for these tissues are a pearlescent pigment and Sumi ink. In making my tissues I use 150 bloom gelatin and coat the melted pigmented gelatin on Denril, a dimensionally stable art vellum. Prior to exposing, the tissues are sensitized using ammonium dichromate mixed with 99% isopropyl alcohol. Exposure times in the plateburner vary dramatically with the density range of the negative. As needed, I will use rubylith masks to selectively increase or decrease density from different parts of the image. Most images require one silver tissue as well as at least 2 black tissues. Occasionally I have needed to use as many as 4 black tissues in addition to the silver tissue to get the final tonal range for a print. All of my images use Melinex Film Type 991, which is no longer in production, as the final support. Post development, the prints are cleared of all remaining chemicals using a 4% potassium metabisulfite solution followed by an extensive wash step. |