Glass Upon Foam Under Projection Printing?

Is there some reason that would not work?
Newton rings? Dust and or scratch problems?
I want my paper flat. Dan

You might have better luck with a vacuum easel. Ebay has some occasionally. I run mine with an old vacuum cleaner situated outside the darkroom and run through a plastic drainpipe into the darkroom. I simply mounted a switch in a box and set it on the enlarger table then ran a cord to the vacuum on the other side of the wall. It does double duty for cleaning up the darkroom and filmholders.

It should work. I've used glass upon foam for rough contact printing. It certainly works well enough for that. Also, contact printing frames were very common decades ago, and still have valid uses. Like Gary says, a vacuum easel works well. One can be improvised from pegboard with little effort. Conventional easels should hold paper flat enough. Paper would have to buckle significantly to affect sharpness. Depth of focus in the paper plane is greater than one might think.

glbeas said:

You might have better luck with a vacuum easel.

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A tacky spray is likely still produced by 3M. Graphics
Arts and printer supply outlets may carry it. Applied
to a surface it will hold sheet material flat while
being exposed. I used it years ago when doing
Processes photography. We called it "sticky
back" and it held sheet ortho film vertically
in the process camera. I've heard of
it being used for print paper.

I ran a test a while back using wetted print paper
sponge dried. A stripped down adjustable borderless
easel, pre-positioned, serves as a platform. Paper nice
and flat. Past 8x10 I'm not sure how a damp sheet of
print paper will handle.

Likely I'll leave the glass sheets to the contact and
proof printers and instead develop wet sheet technique
and methods. Dan

You can also get "post-it" style tape. I've used it on plastic sheet for a tacky easel which worked quite well for several printing sessions with RC paper. I'd hazard a guess that it's life with FB may be a bit shorter. Check the art supply stores for that spray, I think it's still made by one manufacturer or another.

glbeas said:

Check the art supply stores for that spray, I think
it's still made by one manufacturer or another.

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I recall it having been mentioned that the Darkroom
Cookbook has a recipe for a home-brew version of a
similar tacky material. Likely also some hints for it's
usage. Any body got the book? Dan

dancqu said:

I recall it having been mentioned that the Darkroom
Cookbook has a recipe for a home-brew version of a
similar tacky material. Likely also some hints for it's
usage. Any body got the book? Dan

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Yup - " ...

Sticky Easel

The following formula is useful for coating any size peice of plywood to use as an easel for making large blow-ups, as well as for holding prints flat and in place for copying.

Cold Water 16 fl oz or 500.0 ml
Gelatin 2 oz or 60.0 grams
*Corn Syrup 2 oz or 60.0 grams
Glycerin 2 oz or 60.0 grams
Chrome Alum 16 grains or 1.1 grams
Water to make 32 fl oz or 1 litre

*Karo Syrup available in most grocery stores

Mix the syrup and the glycerin in water, and soak the gelatin in this mixture for 10 mins. Then warm it up to 120 deg F / 52 Deg C, and let it set for 15 - 30 minutes with occasional stiring.
Disolve the alum in 60 ml water. Add this to the mixture, and bring the total to 1 litre with water. Strain through cheesecloth. Each ounce of this mixture will cover 100 square inches (a 10" x 10" easel)"

Anchell goes on to say that you should coat the suface on a horizontal support and pour the mixture evenly across, leave for 1 hour to set and apply more coats. He suggests several thin layers work better than 1 thick one.. After the final application, the easel should be left for 6 hours before use. THe unused solution should be kept heated throughout use as once set it can not be remelted. HE goes on to say that, when the finished easel isnt in use, the surface lifespan will be kept to a maximum if it is covered with plastic wrap, clingfilm or wax paper.

Leon said:

Yup - " ... Sticky Easel

The following formula is useful for coating any size peice of ...

Cold Water 16 fl oz or 500.0 ml
Gelatin 2 oz or 60.0 grams
*Corn Syrup 2 oz or 60.0 grams
Glycerin 2 oz or 60.0 grams
Chrome Alum 16 grains or 1.1 grams
Water to make 32 fl oz or 1 litre

*Karo Syrup available in most grocery stores

The unused solution should be kept heated throughout
use as once set it can not be remelted.

Click to expand...

Likely will add some chrome alum to my list of should
have chemicals. I've a good scale and can test small
amounts on various surfaces of various size.
Thanks for the post. Dan

dancqu said:

Likely will add some chrome alum to my list of should
have chemicals. I've a good scale and can test small
amounts on various surfaces of various size.
Thanks for the post. Dan

Click to expand...

That spray can tacky adhesive is 3M ReMount.
A Post-It type. Any office supply might carry.
May be it's good for mounting prints? Dan