Rubylith tape mask makes my digital negative curl

Brett Simison said:

Hi All,

I'm using Pictorico OHP and an Epson 3800 to contact print with Palladium. To get clean borders, I'm trying to use rubylith tape to mask the negative. Unfortunately, it seems the tape is making the negative curl profoundly, enough so that the neg no can longer maintain flat, consistent contact with the paper. Click the thumbnail below to view a large example.

What am I doing wrong?
Thanks!
-Brett

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pschwart said:

Negs need to be perfectly flat while the tape is applied. I used to put the neg on a light table. Tape is a pain. Now I use strips of actual rubylith material that I tack down with Post-it flags. I get a perfectly straight border, I don't waste expensive tape on bad negs, and the rubylith is easily repositionable without leaving any adhesive residue.

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jeffreyg said:

Consider using the rubylith on the glass of the printing frame as well as thick as possible paper under the coated paper to sandwich that against the negative. The black border is helpful but in my experience it doesn't entirely block the UV so the rubylith is the key. You can also place black (opaque) draftsman tape over the mask you have created. a few years ago I printed a limited edition of 14 prints each of 4 images for another photographer who would only accept clean borders and that was the technique that worked.

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Don Bryant said:

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You may also wish to extend the canvas and place a small black border around the image. This helps to align the rubylith. Also you may need to double the thickness of the rubylith to absolutely block the UV.

FWIW, I use a vacuum easel, but when I don't I use a high quality contact printing frame.

Don Bryant

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