Here is a pin registration board I created today for making large color gum prints. It consists of white marker board from Home Depot, a strip of aluminum epoxied to the lower edge of the board to act as a base guide, and three registration pins taped into place on the left. Note: this is the same piece of board I showed in a post from 2016 when I was working in the gumoil process just re-purposed for color printing. It was a plain, flat board back then used for stretching full sized watercolor papers and measures 24″ x 32″. I can tape the pins anywhere near or far apart depending on the size of the print.
The next image shows what it will look like with a full size sheet (22″ x 30″) of Fabriano Artistico Soft Press. The blue mat board is only there to simulate a thin sheet of 24″ x 36″ aluminum to which the paper will be temporarily bonded using Fusion 4000 dry mount film and a heat press. The aluminum sheet will rest on the 3/4″ x 1/8″ thick aluminum bar at the bottom, and will bump up to the registration pins on the left for consistent placement.
Again, having neither the aluminum sheet nor large separation negatives at the moment, I’ve tried to simulate an added piece of extension film with the registration holes punched into it and taped to the negative.
Here are the registration pins. I ordered two different heights, but all have 9/32″ pins. I am not sure which height I will need, but I suspect the shorter ones will suffice.
For punching the holes in the negative extension sheets, I found a 9/32″ hole punch this morning at Staples for $15.
I removed the center punch to give a larger spread between holes. My plan is to punch two holes; one in the center and the other near the bottom. Then I will slide the outer hole punch up to align with the existing center hole and punch a third hole at the top end of the negative extension sheets. This will give me a 17″ span between top and bottom holes plus one in the center.
Before I can use the punch, I will have to cut a slot in the sides at both ends to allow for the wider film. I’ve marked where the metal will be removed.
The advantage of this configuration is that I don’t need an expensive commercial registration punch AND will not need to punch holes in either the paper or the aluminum. In addition the paper will not stretch or shrink while printing multiple layers while mounted to the metal sheet. One down side will be having to align and tape down the pins for each size print. How well does it work? I will find out in the coming weeks as I complete my initial calibrations for gum printing.