Contact printing frame

[koraks]

Most of you who work with these have probably picked your contact printing frame(s) up second hand or even new. When I was looking for one last year, I couldn't find any for a reasonable price, so I decided to construct one myself. I'm not a carpenter, nor a very proficient DIY-er, and I don't have any power tools either. So I wanted to keep it simple, but also wanted to have something that would be affordable, easy to use, to exert enough pressure onto the negative/print sandwich to keep even the most curly carbon tissue flat and I definitely wanted to use a type of glass that would be easy and cheap to replace in case it broke.

So I used the glass of a dirt cheap A4-sized (slightly larger than 8x10") photo frame (ca. $2) as a starting point. I constructed a basic frame with a recessed ledge on which the glass lies. The back of the frame lies on the glass and the pressure is distributed evenly all over the glass and most importantly also on the ledge in which the glass lies. For the back, I used simple 3-layer plywood that I had lying around. I also decided it would be convenient to have a hinged back for POP processes, so I cut the back in half and glued on (composite glue) some hinges.

Initially I tried the frame with the plywood back as it is, but I found it's very easy to break the glass as the pressure doesn't distribute perfectly evenly. Not an issue with normal paper, but it wouldn't withstand the pressure needed to keep carbon tissue flat. So I glued some fibrous material they use underneath laminate floors onto the back. Note: this works OK, but some fibers tend to dislodge and end up on the negatives, prints or the glass, so it's not really ideal, but perfectly workable.

The pressure system relies on 4 lengths of threaded wire that are attached to two pressure bars on the back of the frame. See images for details. I found this way it's very easy to build exactly the right amount of pressure all across the sandwich for whatever printing purpose. This system was inspired by a page I found online, but I presently cannot find it. However, the concept was proudly stolen, I'll gladly admit to that. In the original frame I borrowed this idea from I remember the pressure bars were attached to the frame using hinges, so you wouldn't have to remove them entirely when putting prints into and taking them out of the frame, but I haven't found this to be a hassle anyway.

I've been using this frame for nearly a year now and it's proven to be very reliable and effective. Total cost I don't remember, but somewhere around $25 in parts from a local DIY store.

Some photos say more than the text above. I hope they may serve as an inspiration for those who prefer to construct their own frame for whatever reason. There are many things to improve and vary on this frame, but as it is, it works like a charm. Ignore the poor white balance in the pics; they were quick snaps under difficult lighting.

[koraks]

I didn't really make any plans for this frame. All I did was make a little sketch to get an idea of the lengths of wood I'd need and the crucial parts to keep everything together and whatnot. I then went to the DIY store and looked for cheap bits and pieces that I could use. In some places, a technically more elegant solution was available, but I opted for cheap as it was really meant as an experiment anyway. But it turned out well enough to not revisiting it so far. I'm considering building a slightly larger one to print 8x10" onto A3-sized paper.

[Steven Tribe]

It works.

The comments I have are-

- why not use a light tight glued band between the two halves rather two hinges. It worked fine for heavy duty mahogany plate holders.
- The contact points for the four pressure screws are quite small and will eventually eat away at the wood. If you glued small metal patches underneath the screws you would have better control of the pressure exerted and a longer life.
- The pressure system does take longer than the spring solution. Perhaps a spring solution with several positions is possible?

[koraks]

Steven, you're right in all three respects and I've considered the same things. The hinges work fine, but if I were to build another one, I wouldn't bother with them. On this one I wouldn't gain much replacing the hinges. I will put in the metal plates you suggested when the wear becomes an issue; this will certainly happen in a few months and I'll revise the back by that time. Maybe I'll look for some spring material, but I have to day I like the control and amount of pressure that this solution provides and the materials are much less critical. In practice it works quick enough with the number of prints I make (maybe a couple of dozen a week in a good week). But you're observations are absolutely accurate.

[DKirk]

However, the concept was proudly stolen, I'll gladly admit to that. . .

And I'll be doing the same - can't remember the dilution off-hand, but it's either 3 or 4 (possibly more) parts water to 1 of PVA glue should be enough to paint the fibre board with allowing it to still compress slightly but without casting fibres.

[koraks]

Great tip, dkirk! I may try it out on a bit of leftover board and then apply it to the actual back. Although it also helps that most loose fibers have already let go by now so the problem is sort of solving itself.

[Randy]

Quite a nice printing frame Koraks.

I have had (second hand) an 8X10 contacting frame for years. I have played with 8X10 pre-coated cyanotype paper, printing from 8X10 negs. I recently decided I wanted to mix my own and coat some paper, specifically wanting to print 8X10 negs on larger (11X15) paper as I liked the look of the brush strokes at the edges of the image. I did not have the time (skills / patience) to invest in making a larger frame, nor the funds to purchase one. And since I am one that never throws anything away, I began digging.

I have had this wooden TV dinner tray for probably 25 years - never used it. It's inside dimensions are 20" X 12 3/4".




I dug deeper and found a sheet of glass 1/8" glass with dimensions that just barely fit inside the tray, about 12 1/2" X 18" - I think it came from an old copy machine and already had the edges ground so no risk of cutting. I also had some 1/4" white heavy felt so I cut it to fit the bottom of the tray. I also had two leather beanbag-type bags that must have lead shot in them because they are about 5lbs each - I use them to apply pressure to the glass during exposure.
So that is my contact printing frame.



I have a question - obviously, if I am printing, for instance, an 8X10 neg on 8X10 paper in an 8X10 printing frame, back-loading frames like mine are fine...but...if I am printing an 8X10 neg on 11X15 paper, needing to make sure I have the neg placed where I have coated the paper, it seems to me that my "Frankenframe" is more user friendly. I just lay the paper coated side up on the felt that is in the tray. I can now easily place the neg exactly where I need it to be on the paper, then lay the glass over the neg and add the pressure weights and expose. With the back-loading frame you have to lay the neg on the inside of the glass, then the paper, then the frame back...hoping that the neg doesn't move slightly in the process.

Thoughts?

[Dennis]

For many years now for my platinum printing I use 2 sheets of quarter inch plate glass a little larger than my print size (usually 8x10). I put down one sheet of glass, put the coated paper on it and then the negative on top and then the other sheet of plate glass and clamp it together with the small size industrial clamp. It aint broke so I aint fixen it.
Dennis

[koraks]

I have a question - obviously, if I am printing, for instance, an 8X10 neg on 8X10 paper in an 8X10 printing frame, back-loading frames like mine are fine...but...if I am printing an 8X10 neg on 11X15 paper, needing to make sure I have the neg placed where I have coated the paper, it seems to me that my "Frankenframe" is more user friendly. I just lay the paper coated side up on the felt that is in the tray. I can now easily place the neg exactly where I need it to be on the paper, then lay the glass over the neg and add the pressure weights and expose. With the back-loading frame you have to lay the neg on the inside of the glass, then the paper, then the frame back...hoping that the neg doesn't move slightly in the process.

Thoughts?

Absolutely, and it's certainly an advantage if you were to make multi-layered prints, e.g. gum bichromate or cyanotype over Van Dyke etc. Although in that scenario, you'r probably want to have some sort of registration system that also prevents the negative from shifting as you place the glass on top of the sandwich. With a back-loading frame, positioning isn't that difficult btw. Just grab the print/negative sandwich and place it onto the glass in one go. While holding down the sandwich on one end, place the back as it's split open onto the other half of the sandwich, then close the back and secure it. This way, the shift between the print and the negative isn't any worse than in a front-loading scenario. In fact, when I used a simple picture frame for contact prints, I would run into more difficulties maintaining good alignment when placing the glass on top of the negative.