With the pin register feature you can make multiple exposures from multiple negatives on the same media. For example, to improve contrast of a Pt/Pd print, you can make an exposure, develop and dry the print, then re-coat the paper, place the print and negative back in the printing frame and make another exposure on top of the first with the assurance that both exposures will be perfectly aligned. This feature enables multi-color processes such as gum bichromate with several color separation negatives (typically in the CMYK color space) and even multiple processes such as gum bichromate over cyanotype over platinum.
First, take time to study the details of alternative processes through educational opportunities or by consulting the many excellent resources on the internet including Christopher James’ authoritative volume “The Book of Alternative Photographic Processes“.
1. Create the negative(s) you will use to produce the image and select a medium such as watercolor paper to support your image.
Place the printing frame on a stable surface, face (glass) down. Remove the spring back and set aside. Press a Ternes Burton ST-1 stripping tab onto each of the two registration pins located under the back of the printing frame.
3. Slide a negative between the stripping tabs and the glass, emulsion side up , then attach both tabs to the negative with tape. The illustration shows me attaching a piece of paper. I used blue masking tape just so it is clearly visible in this illustration. I’ve had good results using Scotch Magic tape with both negatives and paper.
4. Optionally, for multiple negatives, repeat the process taking care to align the image on each negative with the image on the first negative before attaching it to the stripping tabs. It helps to place the printing frame above a lighted surface for this step. Make sure each negative is securely attached to the stripping tabs.
5. Remove all negatives except the first one. Place two new stripping tabs on top the negative’s stripping tabs. Slide the printing paper between the new stripping tabs and the negative, emulsion side down. Attach both stripping tabs to the paper with tape. You now have a stack of paper and negative(s) that will remain accurately aligned with each other over multiple exposure and processing cycles. You’re ready to make a print.
(The following step assumes you have coated the paper with a light sensitive compound and that it is completely dry)
6. Place the first negative, emulsion side up on to the stripping tabs. Place the coated and sensitized paper directly on top of the negative so that the emulsion side of the paper is in contact with the emulsion side of the negative. Put the back on the printing frame. Making sure the two holes on the underside of the back line up with the two registration pins on the frame, lock it down. Take a look through the glass just to make sure that everything is okay inside the frame.
7. Expose, process and dry the print. Repeat steps 6 and 7 as needed.
Note: Ternes Burton ST-1 stripping tabs are available from Blick and other sources.