The platinum/palladium printing process was invented by William Willis in the 1870's and patented commercially in 1879. By the turn of the century platinum prints were very popular, valued for their beauty and their intrinsic permanence. Platinum and palladium are two of the most inert elements (noble metals) in existence which contributes to the archival stability of platinum/palladium prints. With the onset of World War I, platinum family metals were hard to come by in the US and platinum papers had to be imported from Europe. By 1941, commercially produced platinum papers were no longer available. Contemporary print makers who desire the unique and beautiful qualities of this process create their own printing paper by mixing the light-sensitive chemicals and coating paper by hand. Many print makers thrive by working this way, gaining both technical control and personal satisfaction from this hand-made approach to photographic print making. The process involves mixing small quantities of a sensitizer solution (ferric oxalate) with solutions containing the platinum and/or palladium metals. This mixture is then applied to fine rag paper or other media, using either a brush or a glass rod which evenly spreads the solution across the paper. The platinum mixture is only sensitive to ultraviolet light and is therefore a contact printing process (the negative must be the same size as the desired print). The platinum and palladium becomes embedded within the fibers of the paper which results in an image that is as permanent as the paper itself.
The prints below were scanned b&w. The prints have a slight sepia tone which is normal for platinum/palladium prints.