Re: Gum prints with an enlarger (UV loss)

Larry Bullis (lbullis@ctc.ctc.edu)
Tue, 16 Jan 1996 14:00:36 -0800 (PST)

> By chance, I happened to have access to a vacuum easel that was left
> over from someone's attempt to do dye transfer. This was a professional
> dye transfer easel (made by Condit, I guess - lots of $), but in
> principle it shouldn't be hard to fabricate on your own. Anyway, this
> was the type of easel that had concentric grooves cut into it for the
> vacuum that corresponded to the standard paper sizes. This is designed
> to hold the paper flat at the edges rather than lots of little holes
> all over that would end up showing in the image. The vacuum comes from
> a single point in the groove (you could apply vacuum to any single
> groove by moving the tube from the pump, but the point was to only use
> the size groove that fit the exterior dimensions of your paper. I
> realize that this is a sketchy description, it is really simple. If
> there is interest, I'll try to do an ascii drawing and post it, but it
> will take time.

You can easily build something that will work. The way I did it was to
take a piece of masonite and a piece of pegboard, both the same size, and
build a box with onextwos on the sides. In the inside, it needs more
onextwos that have air channels (in other words, these supports don't go
end-to-end, but have gaps. These keep the frame from distoring when the
vacuum comes on. To accomplish the same purpose as the grooves in the
expensive condit easel, all you have to do is block the holes that aren't
covered with your printing paper. It is helpful to have a variable leak
control to use just the amount of vacuum you actually need. There are
numerous ways to do this. On one unit, I built a little slider valve,
but Rainbow vacuums have a leak control device on the hose.

The hardest part is to devise a fitting for the hose connection. Old
vacuum cleaner hoses from Goodwill might work. I used PVC parts.

These easels can be really great, and also work for vacuumforming.

Larry Bullis