A simple, but effective OHP negative registration technique for gum printing. The method can be used for multiple pass single negative prints as well as CMYK negative prints.
I was asked to write this article to share a simple, but effective OHP negative registration technique that I have been using for Gum printing. But, before I go any further, I want to be clear that I am not a veteran gum printer and others may see flaws in the method that I am not seeing. That said, the method seems to be working just fine for me. I have been using this technique for multiple pass single negative prints as well as CMYK negative prints.
1Print the negatives with registration marks or cropping marks. I use the corner cropping marks. I also select “labels” so the negative prints with the file name to eliminate confusion about which negative is which.
2Stack the negatives and line up the registration marks. I find that simply aligning the sheets almost always results in the registration marks lining up. Then clip the edges together using stiff clips of a similar type shown here.
3Lay the stack on a cork board push two push pins in diagonally opposite corners of the stack. Be sure the pins go in straight and all the way through the
stack and well into the cork board. The negatives are now registered with each other so you simply need to align it on the paper and transfer the registration holes to the paper. The negatives are now registered with each other so you simply need to align one negative on the paper and transfer the registration holes to the paper.
4With one one of the negatives lined up on the paper, push a pin through each of the two holes. Then using acid free tape, tape the negative to the paper and remove the pins. Now everything is registered and you can use the holes with each subsequent pass. Be sure to “feel” for the holes before pushing the pin in to avoid creating a new hole. Remove the pins and you are ready to expose the print. Repeat as needed for all the passes.
The only drawback to the method that I have found is that it leaves two small holes in the paper outside the print area. I found that I can minimize the impact of the holes by burnishing them from the back with a spoon or something similar. You could use a larger negative and move the hole further out to the corners if desired.
That’s it. Pretty simple but it works for me.