Temp is key and you cannot trust the T Meter
Warmup takes at least an hour
Originally Posted by cowanw
Temp is key and you cannot trust the T Meter
Warmup takes at least an hour
Tin Can
As I said (about the over-and-under drying line method)...its not perfect - just keeps things from getting too curly before I place the dried prints between sheets of four ply mat board, with a weight on top - where the prints stay for several days.
My alternate to the two-line method is to use one line, and simply flip the prints over while still just a bit damp - before they've had a chance to curl on the bottom edge. Then...between the mat boards and under the weight they go!
Not all papers are the same. Some curl more than others; it's also related to age and not just ambient humidity. Regardless, ALL fiber-based papers need to be compressed after drying before they're flat enough for drymounting. And even then the whole thing will tend to bend unless stored under pressure, stacked. This is just a fact of life with any kind of thin sheet material with a differential between face and rear. The back responds to humidity differently than the emulsion side.
Washing is an independent question. After mine are washed, I place them face up on fiberglass screens to air dry for at least a full day. Then they are placed under a heavy large sheet of plate glass in small stacks for a number of days until I get around to spotting them and sorting them out for what I think deserves drymounting or not. Then prints and mounting board always need a little pre-drying in the press prior to actual permanent mounting. But if one wants to flatten them in the press between sheets of museum board once they're air-dried, that's fine too. Just don't overdo it with too much heat or time, which can embrittle the emulsion. But that won't guarantee they'll stay flat over time. Depends.
After washing and drying, store prints alternately face up and face down under moderate weight. This keeps them flat until you are ready to mount them.
I've checked the alignment of the press and the temperature across the platten. I've tried this with different paper above and below the print, I've tried a silicone envelope and watercolor paper. Problem is, prints dry too fast. They are dry when they go into the press. I've tried 45 sec 10 sec of air and another 30 all the way up to 6 minutes. I've tried 180 to 230 degrees.... believe me, I've TRIED a LOT!
thx! and I won't quit!!
Gosh. ... I hope some of you never try to make plywood. If the front and back of a hydroscopic sheet of material have different coefficients of permeability, warping or bowing is a fact of life. And that is INHERENTLY the case with EVERY fiber based emulsion-faced printing paper ever made. You gotta somehow flatten em under compression once dried, and then either mount them onto a flat substrate or keep them stored under a degree of compression.
As far as going borderless, that won't leave you any safe handling edge, or ability to trim off any misaligned drymount tissue properly. And do you want every single image cropped exactly the same proportions? But whatever.
Would you pay the same for a sheet of plywood you had to cut two inches off each side before you used it? And how would that work with 16-inch-on-center trusses?
The prints are drying in 3 hours, 4 hours at 45% humidity. The wrinkles dont 'flatten out' the edges become 'crinkled' Look at the right photo in the post.
I dont have the option of mounting everything. The prints I am making need to be unmounted. And as far as borderless, I don't need to trim any tissue because they are UNMOUNTED.
thx!
The discussion on other thread indicated that this 'ripply' curling on the long edge of the paper seems random. It has been very time consuming for me to to flatten some of these prints - up to 20-30 minutes in a dry-mounting press.
I have not encountered this problem with the paper from a new box I started this past weekend (bought in 2022); I have made approx. 40+ prints. My process has not changed - go figure.
A friend of mine suggested that if the problem persisted, I should print on 12x16 paper and trim! He is obviously out of touch with the cost of paper.
I'd pay for the best plywood relative to the application in mind within realistic budget. And sure I'd trim it. I trim all my prints too. And "Gosh"... I was a buyer for a major construction supplies company for 40 years, prior to retirement, so know darn well the degree sheet goods were adapted to real world applications.
But in your case, is the wrinkled edge always on the same side in relation to how it was being stored to begin with? Being older paper, it appears to be symptomatic of long-term humidity affecting one side much more than the whole sheet, and even impacting the aging of the gelatin differentially. Admittedly, a hard problem to correct and keep corrected, without trimming. I'd simply buy new paper and keep it stored under better/drier conditions. Sorry I don't have a better answer, and just a realistic one.
Tin Can's advice is not universally applicable. Drymount presses can be tested for thermostat accuracy using special monitoring strips, and if necessary, a replacement thermostat or dial installed. Most presses reach temp equilibrium within about half an hour unless the room is quite cold.
All Brand New paper, bought from BH. (next fox will be from someplace else) And as for the press, I've dried them 4 up, one single, I marked the edges and rotated them... rotated at half time too. It melts MT5 just fine so I dont think it's mechanical in the press.
Humidity is horrendously dry here.... going to be 10% today, everything dries much too fast, and the way it dries off the edge of the print is not equal where the bends are. The paper has to be compressing and then not releasing equally.
I'm going to mess with it some more today. Try one face up with the humidifier blowing on the paper side from below.
I've got some years in construction too, with 800+ houses under my belt and I'll say this: If plywood sheeting doesn't fit on center, something is wrong. No carpenters are going to put up with trimming every sheet. ;-)
Thx!
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