Digital Copies of Darkroom Toning

I work in the digital darkroom these days; it has been quite a while since I have been in a traditional "wet" darkroom. But, there are times when I have the longing to duplicate the tones created in the traditional darkroom. True sepia, selenium, silver, cyanotype,platinum, palladium, and silver gelatin all had different amounts of tone deposited between the highlights and shadows. Depending on the artists technique, the intensity varies as well. Recently, a fine art photographer, friend was lamenting her dismay at trying to duplicate her silver gelatin technique in Photoshop. Searching the web, I found a technique on ePaperPress for copying a tone. The technique requires selecting a quarter tone, a midtone, and a three quarter tone and using a grayscale version converted to RGB and a copy of the original toned image then constructing a Curve adjustment. It works pretty well; check it out.