Gelatin over-coating of inkjet prints

[Peter De Smidt]

I'm interested in trying out putting a gelatin over-coat over an image printed on fine art paper with an inkjet printer. Anyone have suggestions as to a good way to do this?

[sanking]

I'm interested in trying out putting a gelatin over-coat over an image printed on fine art paper with an inkjet printer. Anyone have suggestions as to a good way to do this?

Peter,

One of the problems with gelatin solutions is that a large number of bubbles are created as you spread it on a paper. One way to get around this is to first spread the gelatin solution on the print, and then use a threaded coating rod, heated to 150F-170F, and roll it over the coating. The rod will push bubbles and debris to the side, leaving you with a perfectly even surface.

I would suggest a gelatin solution of about 5%, and a formed rod that will leave a wet height coating of about .2 mm. Check out RD Specialities for formed coating rods.

I use a very similar technique for sizing art papers for carbon transfer printing, the only difference is that I use a RD-200 rod that leaves a wet height coating of about .45 mm, and a 7% sizing solution.

The idea of gelatin over the inkjet papers seems nicer, and safer, than other poly type coatings, which may be easier to apply but you can not be as sure as to their long term stability, whereas gelatin is for the ages.

Sandy

[Peter De Smidt]

Thank you, Sandy! I'll give it a go.

[sanking]

Thank you, Sandy! I'll give it a go.

Peter,

I forgot to mention that RD Specialities has a set up charge for the formed rods, unless you purchase five or more.

However, I believe a regular stainless steel rod would work ok for your work, and you can buy them from many sources. If you have a look at the attached .pdf document you will find a file of minimum and maximum diameter for rod sizes. Subtract the minimum from the maximum and that will give you the thread height in inches in inches. You can then convert to mm if desired. For example, if you look at Di Min and Di Max for a 3/4" 10 thread stainless steel rod you will find the figures of .7482" and .7288". Subtract the smaller figure from the larger and you will get a thread height of 0.01964", which is 0.492 mm.

I can not say for sure what thickness you need for the application you plan to do, but with the attached file you can make the calculation and buy the rod you need.

Sandy

[Peter De Smidt]

Thank you, Sandy. I had noticed the set-up charge. A regular stainless steel threaded rod should be good enough to do some experimenting with.

In discussions with other experimenters, it's come out the mold can be a problem in high humidity areas. Unlike carbon transfer prints, these won't be blasted with UV or coated with a dichromate. Some anti-mold candidates that have been suggested are Thymol, Phenol or Kathon. Do you have any experience using one of these or something similar?

[sanking]

Thank you, Sandy. I had noticed the set-up charge. A regular stainless steel threaded rod should be good enough to do some experimenting with.

In discussions with other experimenters, it's come out the mold can be a problem in high humidity areas. Unlike carbon transfer prints, these won't be blasted with UV or coated with a dichromate. Some anti-mold candidates that have been suggested are Thymol, Phenol or Kathon. Do you have any experience using one of these or something similar?

Yes, you can add a few drops of a 30% solution of thymol in alcohol to the gelatin solution. That would be 30 grams of thymol and add alcohol to make 100 ml of solution. It will prevent mold. The others might work as well but I have always had good success with phenol.

I sometimes add a few drops per liter of the thymol solution in the summer when the humidity is high and the tissue takes a long time to dry.

Sandy

[bob carnie]

Peter

We tried putting a gelatin glop over a very large inkjet print , unfortunately I was not involved making the glop and our idea was to protect the print for glassless presentation.
After a couple of days the ink started bubbling up through the gelatin like nuclear explosions.. I would like to make this work as I think it would make a super presentation.
In our case we mounted the print to diabond and then put a secure floater frame around the diabond to create a snug fit, then we basically calked the back so when pouring in the glop it would settle and form like one of those big resin prints that seem to be popular.
I thought that this would be great , but the excecution of the idea failed.. I will follow your thread and maybe see where we went wrong. I would like to make this work.

[Drew Wiley]

Hint: ordinary old-fashioned yellow Listerine contains thymol and works great to
retard mildew etc.

[sanking]

Peter

We tried putting a gelatin glop over a very large inkjet print , unfortunately I was not involved making the glop and our idea was to protect the print for glassless presentation.
After a couple of days the ink started bubbling up through the gelatin like nuclear explosions.. I would like to make this work as I think it would make a super presentation.
In our case we mounted the print to diabond and then put a secure floater frame around the diabond to create a snug fit, then we basically calked the back so when pouring in the glop it would settle and form like one of those big resin prints that seem to be popular.
I thought that this would be great , but the excecution of the idea failed.. I will follow your thread and maybe see where we went wrong. I would like to make this work.

Bob,

I want to make sure that folks understand that I have never done this myself and only suggesting a procedure that I believe might work based on my experience with coating art papers for carbon transfer printing. I definitely believe that you would want to put a very thin coating on a ink jet print and that pouring in the glop as you describe would cause numerous difficulties and also give a lot thicker coating than would be necessary.

So from a strictly theoretical perspective I believe that one should start with a fairly low gelatin percentage, probably no more than 3%-5%, first spread it evenly and then roll a *very hot* (170F-190F) rod over the coating. And you need to do this fairly quickly because a heated metal rod cools off pretty quickly once you pull it from the water. If you used a coated rod that left a wet height of 0.2 mm the coating will dry down to less than 1/10, maybe 1/20, of that thickness, so the final surface coating would be quite thin but it would still do the job of protecting the print, and also give it a bit more shine if that is desired.

One might also want to add a small amount of a gelatin hardener to the coating, formalin, glyoxal, etc. I have had some problems with glyoxal yellowing im the fairly thick coating I use for sizing art papers but I don't believe this wold be an issue with thin coating, and you avoid the very unpleasant and dangerous formalin fumes.

Sandy

[Drew Wiley]

Bob - those pigments are held in a glycol which dries very slowly, compared to mere
appearances. How long did you let the print "cure" first? (I'm implying how many MONTHS).

[bob carnie]

Drew
That may be a good reason, the print cured all of 8 hours , I am impatient.

Bob - those pigments are held in a glycol which dries very slowly, compared to mere
appearances. How long did you let the print "cure" first? (I'm implying how many MONTHS).

[bob carnie]

In my naivety , I was trying to mimic a resin look that has a very , very thick coating and looks very slick. I was amazed at the pretty patterns though that bubbled up through the glop. Just couldn't sell it.

Bob,

I want to make sure that folks understand that I have never done this myself and only suggesting a procedure that I believe might work based on my experience with coating art papers for carbon transfer printing. I definitely believe that you would want to put a very thin coating on a ink jet print and that pouring in the glop as you describe would cause numerous difficulties and also give a lot thicker coating than would be necessary.

So from a strictly theoretical perspective I believe that one should start with a fairly low gelatin percentage, probably no more than 3%-5%, first spread it evenly and then roll a *very hot* (170F-190F) rod over the coating. And you need to do this fairly quickly because a heated metal rod cools off pretty quickly once you pull it from the water. If you used a coated rod that left a wet height of 0.2 mm the coating will dry down to less than 1/10, maybe 1/20, of that thickness, so the final surface coating would be quite thin but it would still do the job of protecting the print, and also give it a bit more shine if that is desired.

One might also want to add a small amount of a gelatin hardener to the coating, formalin, glyoxal, etc. I have had some problems with glyoxal yellowing im the fairly thick coating I use for sizing art papers but I don't believe this wold be an issue with thin coating, and you avoid the very unpleasant and dangerous formalin fumes.

Sandy

[Drew Wiley]

I'm really surmising, because I haven't tried it, but it's probably the same reason
why inkjets don't seem to like drymounting - the temp per se. If it works at all, it
would probably have to be a gelatin with an especially low melting point.

[Greg Miller]

I'm wondering if a blow dryer would help with the glycol situation (and Bob's impatience). It seems to be beneficial when trying to speed up glycol evaporation on RC papers to reduce the impact of outgassing.

[Drew Wiley]

Greg- forced air drying is tricky where glycol is concerned. Too much heat and it gets tacky quick. Just depends how much glycol and how the pigments are bound. Since injet colors are complex blended composites, it's hard to say without testing.
My suspicion is that there simply is no substitute for a full natural cure over time.
There may also be different patterns of behavior with diffent brands of ink and paper.

[Ed Kelsey]

How about trying Breathing Color's Glamour II varnish? I use it for canvas prints but it also works on paper. I'd recommend dry mounting before coating though. I use a roller.

[Drew Wiley]

Again, Ed, drymounting is probably out due to the heat, and some type of cold mtg
instead. Those who have scrap inkjet prints can experiment. But my own experience
tells me to watch the long-term results before making something a commercial
option. Many short-term successes fail over time. (My own walls contain numerous
big prints with blisters or ripples in the mounting which disqualifies these prints for
sale - but there is nothing more authoritative than learning the options by actually
attempting them. So far everything which has gone to the public has held up, but
simply because I tested first!) And I test in various climates too!

[PViapiano]

Mark Tucker, a fantastic photographer, featured a post on his blog with pics, concerning this very subject:

http://marktucker.wordpress.com/2010/11/12/printmaking-with-varnish-removes-guilt/

[sanking]

Well, I just coated an inkjet print with the method described earlier. I used a 5% gelatin solution, heated to about 120 F. I soaked an inkjet print made with K7 inks on an Epson 7600 and squeegeed it to a level surface. Meanwhile I put the coating rod in a tube of very hot water. I then poured enough gelatin solution to cover the print to a wet coat thickness slightly greater than the height of the threads on the rod (and a drop of glut to the solution to harden the gelatin) and spread it evenly with my hand. I then rolled the hot rod over the print.

The technique worked perfectly. However, though the gelatin coating may add some protection to the print when dry it hardly changed the appearance of the print. The print is on matte paper and once the gelatin coating dried it still looks much like it did before I coated it, quite matte in appearane.



Sandy

[paulr]

Have you considered some kind of varnish? I experimented with varnishing inkjet prints for a book project. Some of the results looked amazing. Unfortunately I gave up before finding an efficient and reliable way to do it. I was air brushing water-based varnishes, and the amount of work and fuss was crazy-making.

But it looks a hundred times easier than working with gelatin! Maybe someone else has figured out a smarter way than mine.

[jnantz]

the starn twins seem to do something like this as well
they use encaustic wax to overcoat their prints ...
maybe gelatin is easier or completely different ...

[sanking]

Have you considered some kind of varnish? I experimented with varnishing inkjet prints for a book project. Some of the results looked amazing. Unfortunately I gave up before finding an efficient and reliable way to do it. I was air brushing water-based varnishes, and the amount of work and fuss was crazy-making.

But it looks a hundred times easier than working with gelatin! Maybe someone else has figured out a smarter way than mine.

I have tried varnishing it but also found the procedure incredibly time consuming and messy. Also, I have many concerns about the long term effects varnishing may have on a print.

The attraction of gelatin is that it should offer protection to the print and enhance its archival qualities, not damage them. However, without question the technique I used would be fairly difficult to master as well. It is relatively easy for me but only because I am bringing to the table years and years of sizing art papers for carbon transfer printing.

Sandy

[Jim Becia]

Peter,

A few posts up, a mention is made of using Breathing Colors coating materials. I tried it on a photo printed on fine art paper and it turned out extremely nice. If you want, you can send me a small photo and I can put a coat or two on it and send it back and you can decide it it works for you. Jim Becia

[D. Bryant]

(and a drop of glut to the solution to harden the gelatin)

Ah, you have been hardening with glut!


once the gelatin coating dried it still looks much like it did before I coated it, quite matte in appearance.


That's been my experience as well, that is the paper surface dries essentially mat.

Don Bryant

[sanking]

Ah, you have been hardening with glut!

That's been my experience as well, that is the paper surface dries essentially mat.

Don Bryant

Don,

Yes, and since I started using glut my abdomen has gotten incredibly hard!!

BTW, how did Hydrocote work for you?

Sandy

[paulr]

I think there are varnishes with excellent archival properties ... one that pass accelerated aging tests without yellowing or cracking. The trouble I had is that the oil-based ones need a spray booth and a long drying time, and the water-based ones are tricky to apply smoothly.
I found that the Golden Paints products were excellent and so was their tech support. My air brush setup, however, was crappy, and my attention span short.

[D. Bryant]

Don,

Yes, and since I started using glut my abdomen has gotten incredibly hard!!

BTW, how did Hydrocote work for you?

Sandy

Without writing a long post the results of the Hydrocote weren't worth the trouble and in the end I just didn't care for the plastic look it imparted to the print.

I wish Peter luck with the gelatin but frankly I would stick with the liquid coating product Breathing Color, which has gotten a lot of positive reviews including Dan Burkholder whose judgment about such things I trust.

These days I really like the baryta glossy inkjet papers (unfortunately the Harman Gloss AL was discontinued) and some mat papers which I spray with Premier Art Sheild for protection.


Don

[Drew Wiley]

The notion that any kind of varnish or lacquer overcoat is going to be "archival" should be taken with suspicion. For one thing, no actual aging tests have been done with this kind of combination; second, you may end up with the varnish and substrate cross-linking or aging at different cycles of expansion/contraction. Maybe
you might get some useful information if you made some tests and set them aside
in some relevant display area for a decade or so, but the whole terminology of
"archival" has gotten so loose in this field already that it makes little sense to throw
in a completely unknown monkey-wrech and risk your reputation.

[D. Bryant]

The notion that any kind of varnish or lacquer overcoat is going to be "archival" should be taken with suspicion. For one thing, no actual aging tests have been done with this kind of combination; second, you may end up with the varnish and substrate cross-linking or aging at different cycles of expansion/contraction. Maybe
you might get some useful information if you made some tests and set them aside
in some relevant display area for a decade or so, but the whole terminology of
"archival" has gotten so loose in this field already that it makes little sense to throw
in a completely unknown monkey-wrech and risk your reputation.

What specific research do you base your statement on?

Don Bryant

[Greg Miller]

Greg- forced air drying is tricky where glycol is concerned. Too much heat and it gets tacky quick. Just depends how much glycol and how the pigments are bound. Since injet colors are complex blended composites, it's hard to say without testing.
My suspicion is that there simply is no substitute for a full natural cure over time.
There may also be different patterns of behavior with diffent brands of ink and paper.

I probably could have been more clear, but I meant to suggest that the print itself could be blow-dried prior to the gelatin coating. Hopefully this would eliminate the problem Bob had with the ink bubbling up after waiting only 8 hours for the ink to dry.

[Peter De Smidt]

One reason I'd like to try gelatin is that eventually I'd like to size art papers for carbon printing, and so the skill gained with one endeavor should help with the other. In addition, I can deal well with fairly toxic liquids. It's fumes that I'm not equipped to deal with. Thus, even if I have to add some anti-mold and hardener it should be easier to deal with than spraying lacquer. I'm going to get some samples over-coated with the breathing color product, and it'll be interesting to compare the results. I appreciate all of the input!

[D. Bryant]

Greg- forced air drying is tricky where glycol is concerned. Too much heat and it gets tacky quick. Just depends how much glycol and how the pigments are bound. Since injet colors are complex blended composites, it's hard to say without testing.
My suspicion is that there simply is no substitute for a full natural cure over time.
There may also be different patterns of behavior with diffent brands of ink and paper.

Drew,

I know several people who routinely quick dry digital negatives with a hair dryer. I don't think it's as risky as you suggest, not by my experience though best practice is to inter-leave fresh prints with virgin bond printing paper and allow them to dry and out gas for 24-48 hours. I think todays high quality inks are much less prone to problems of drying compared to what they were just a few years ago, in fact I know they are.

Also once properly dried, ink jet prints can be dry mounted by using the proper dry mount tissues. The new baryta coated 100% cotton fiber papers and the 100% cotton mat papers show no issues dry mounting.

Don Bryant

[D. Bryant]

One reason I'd like to try gelatin is that eventually I'd like to size art papers for carbon printing, and so the skill gained with one endeavor should help with the other. In addition, I can deal well with fairly toxic liquids. It's fumes that I'm not equipped to deal with. Thus, even if I have to add some anti-mold and hardener it should be easier to deal with than spraying lacquer. I'm going to get some samples over-coated with the breathing color product, and it'll be interesting to compare the results. I appreciate all of the input!

I'll just note that I gelatin coat with foam brushes and never get uneven streaks or to put it another way I get even coatings. However, unlike Sandy, I'm not coating to obtain the same gelatin depth that he needs for carbon transfer.

I think you will find coating a bit easier by using a mask over the print to obtain a specific thickness but you probably know this already.

Good luck,

Don

[D. Bryant]

Without writing a long post the results of the Hydrocote weren't worth the trouble and in the end I just didn't care for the plastic look it imparted to the print.

Don

I do want to add a few more comments about the Hydrocote polyurethane.

This product is non yellowing water based aliphatic compound which has been widely used in much more demanding applications than coating prints. The stuff just doesn't yellow and is hard as nails.

And I think the satin finish maybe apropos for carbon on aluminum to protect the surface and to prevent the release of the carbon pigment from the aluminum surface. IMO, it would be best applied with a high volume low pressure sprayer.

As for spraying prints with materials that cause airborne fumes, I've set up a small spray booth in my garage made from a large cardboard box. This isolates the fumes from my living area and allows for an easy exchange of fresh air. I simply wear a vapor mask to block inhalation of particulate material and keep a fan moving air to prevent stagnation. Dan Burkholder built a movable spray booth from PVC tubing which can be rolled outdoors during good weather for spraying the Breathing Color.

The last thing I'm concerned with using these materials is yellowing. At this point in time I regard it as a non issue. Nothing is ever certain but as long as the print surfaces don't fade, degrade, or discolor in my lifetime I'm happy. :)

I've seen some very old platinum/palladium prints that have discolored from poor processing so compared to our current knowledge about materials, processing, and preservation we are way more advanced in that arena than in the beginning of photographic printing. And we have a longer history of putting ink on paper than people think about too. Even so, these materials beg testing for longevity and archivability. The Aardenburg Imaging & Archives may at sometime be able to test esoteric material combinations and even non ink jet prints or traditional wet prints. We can only hope.

Don Bryant

[Drew Wiley]

Hi Don - a couple of potential problems here, but both involve the fact you've got a
moving target which will require frequent retesting. First, "research" is meaningless
if you're talking about the long-term performance of combined systems which have
only been on the market very,very briefly - you can't get realistic accelerated aging
tests of the effect of cross-linking and bonding. What will work for a temporary trade show display might fail under longer periods. Or it might not. Anyone who says otherwise has to be adding a significant BS coefficient. How do you get long
term data without any long-term observation? The second problem - and glad
to hear inks are improving in terms of drying and mounting - is that these chemicals
are under EPA scrutiny. Which means they might (or might not) get changed without
anyone being told the details. In other words, what works today might not work
tomorrow. Maybe the printing industry including inkjet will get a pass, maybe the
EPA itself will be defunded by anti-Fed activists, or maybe glycol will in fact get hit in this trade just as it is beginning to in industrial coatings. Just the nature of the
game.

[D. Bryant]

Hi Don - a couple of potential problems here, but both involve the fact you've got a
moving target which will require frequent retesting. ...

Well Drew I guess that's all very interesting but your reply fails to answer my question directly.

Don

[Drew Wiley]

Sorry, Don ... but having been involved with the coatings industry off and on for
several decades, one thing I have learned is, unless you know your sources are very
reliable, take everything with a grain of salt. Likewise, having dealt with quite a variety of print mounting systems, I have run across a tremendous amount of
misleading BS in mfg tech literature and even directly from mfg cust service techies over the phone, and have come to the conclusion that you either need to know someone who has done hard testing, or you need to do it yourself. I have a hard time thinking of anyone as an "expert" when I've done four times the testing they
have on an analogous problem. Certainly doesn't mean they're all incompetent, just
most of them, and that's not an exaggeration.

[D. Bryant]

Sorry, Don ... but having been involved with the coatings industry off and on for
several decades, one thing I have learned is, unless you know your sources are very
reliable, take everything with a grain of salt. Likewise, having dealt with quite a variety of print mounting systems, I have run across a tremendous amount of
misleading BS in mfg tech literature and even directly from mfg cust service techies over the phone, and have come to the conclusion that you either need to know someone who has done hard testing, or you need to do it yourself. I have a hard time thinking of anyone as an "expert" when I've done four times the testing they
have on an analogous problem. Certainly doesn't mean they're all incompetent, just
most of them, and that's not an exaggeration.

As I said Drew you aren't addressing or answering my question with specifics. I'll take that as an answer that you don't know. If you are such an expert whip out some proof regarding your assertions about the specific materials under discussion not general answers that anyone could come up with.

Or to state it another way, you don't regard Aardenberg Imaging as a reputable testing resource. Is that what you are suggesting?

Don

[Peter De Smidt]

Skepticism is warranted about manufacturer's claims for print coatings. Historically, most made matters worse in the case of silver gelatin prints. With ink jets, though, there is a greater need for a coating, as the micro-porous ink receptor coating acts like a sponge, whereas with a sg print, the dried gelatin acts as a barrier. With pure carbon pigment ink sets, I expect that the biggest long term danger to prints will be air born contaminates, although I have no way to prove this. And that's the thing, we can only truly prove this type of thing with hindsight. All we can do now is to work with the best info we have, and that'll never be conclusive.

[bob carnie]

hi Drew
I want to take this a little off topic but I think relevant since we are talking about overcoats, I would like to address under coats - mounting tissue.**If this needs to go to another thread then I will start one there**
I am interested in your and others thoughts about the archival attributes of mounting prints.
I am preparing a rather large show right now of my own work and some of these prints are large silver gelatin and need mounting to diabond* heat mount* Drytac makes a ph nuetral adhesive that will work and using it in the past I have been happy with the results.
Along the same lines I am about to mount rag paper to melemex and aluminum to be used in multiple hit alt printing and use cold mount adhesive which again Drytac has assured me is ph nuetral acid free and has archival attributes that I am looking for.

In your and others opinions do you think this method of preparation archivally responsible. I plan to work with multiple hit silver and alt a great deal in the future and the only way I can imagine it working is to mount the prints.
I have seen prints being rolled **stripped** the image layer, with a large roller , actually an old technique used to strip colour prints and then place on canvas to stretch.
I would prefer to not go there but would if I thought the mounting tissue would adversely attack the emulsion of the printed surface.

I have to add I had two Irving Penn multiple hit platinum prints in my shop last summer to be de framed and put up for auction.. they were paper mounted to aluminum still attached.
Both prints went for $176,000 so I assume the market agrees that dry mounting to aluminum is not an issue.

So like those worried about what goes on a print , I am also worried about what goes under the print as well.

thoughts.


Sorry, Don ... but having been involved with the coatings industry off and on for
several decades, one thing I have learned is, unless you know your sources are very
reliable, take everything with a grain of salt. Likewise, having dealt with quite a variety of print mounting systems, I have run across a tremendous amount of
misleading BS in mfg tech literature and even directly from mfg cust service techies over the phone, and have come to the conclusion that you either need to know someone who has done hard testing, or you need to do it yourself. I have a hard time thinking of anyone as an "expert" when I've done four times the testing they
have on an analogous problem. Certainly doesn't mean they're all incompetent, just
most of them, and that's not an exaggeration.

[sanking]

I have to add I had two Irving Penn multiple hit platinum prints in my shop last summer to be de framed and put up for auction.. they were paper mounted to aluminum still attached.
Both prints went for $176,000 so I assume the market agrees that dry mounting to aluminum is not an issue.

So like those worried about what goes on a print , I am also worried about what goes under the print as well.

thoughts.

My opinion is that a print well mounted to an aluminum or Dibond (epanel) surface would be in the long be much more likely to survive than if simply left as a paper print without any type of mounting. There are ways it could be destroyed, of course, but there are about 90% more ways a plain paper photograph could be ruined.

Sandy

[SocalAstro]

Peter,

You can then convert to mm if desired. For example, if you look at Di Min and Di Max for a 3/4" 10 thread stainless steel rod you will find the figures of .7482" and .7288". Subtract the smaller figure from the larger and you will get a thread height of 0.01964", which is 0.492 mm.

Sandy

Sandy,

The thread height is actually half of .019" :-)

-Leon

[Drew Wiley]

Don - I can't comment at length at the moment. Traditionally, hand-coated alt process prints have been hinge mounted for the sake of archival properties and to
preserve the look of the special paper itself. What happens in auctions is sometimes a
fluke. An auctioneer I know (or rather, the tech who prepares the prints for auction)
would never, ever drymount a platinum. Silver is a different topic. The problem with
aluminum is that, if it is a simple sheet other than a composite like Dibon, it is a very
poor insulator, and without an additional backer, easily leads to condensation and foxing (mildew) under certain circumstances. It's considered more of a display option,
though certainly elegant for color prints and other glossies if properly backed and
covered with acrylic, which again, is not as prone to condensation as real glass....
The other question, is that accelerated aging like Aardenburg, Wilhelm, and maybe
others do is not really a great indicator of how overcoats perform in the long run.
You torture them in a chamber and they simply melt or fail in a manner quite different
from aging failure. I don't have time to argue with you about this, but I professionally
field this kind of information to a variety of trades. I'm not guessing, but am working
with known probabilities. Without specific long-term testing, you take your chances.

[Kirk Gittings]

The problem with not dry mounting either silver or ink prints (even ink on very heavy papers) at sizes above 11x14 is warping, I suspect due to temperature fluctuations. So any larger prints I always dry mount and have Never had any complaints from museum curators or knowledgeable collectors.

I have never tried aluminum. What are the costs like for say a 20x24 sheet?

[Drew Wiley]

Kirk - high-qualtity substrates like Dibond are very expensive compared to traditional
drymounting and are generally reserved for mounting big color prints, especially high
gloss like Ciba or Fuji Supergloss which are prone to "orangepeel" on paper or fomeboard substrates. This is generally done with a hi-tack acrylic cold mount adhesive - again, a lot more expensive than drymounting and a helluva lot more unforgiving. Very large fiber-based silver prints are a lot easier to wet mount on a
vaccum press if one know correct technique. Once you involve a nonporous plastic
or metal on either surface, the game changes.

[bob carnie]

Silver prints are heat mounted onto diabond as well as rag,we have never cold mounted a fibre print, and I have never heard of wet mounting a fibre print and would be curious as to how it is done.

The platinums I saw were ones that the paper was coated both sides of the aluminum then this complete mount was punched and then multiple hits of platinum were exposed using registerd film . I have never mounted an existing platinum print but would consider it over 30x40. The mounting for platinum is for multiple coatings and multiple hits.

With diabond to get rid of the orange peel we use optically clear face mount adehisive. The material as Drew states is very expensive.
Just a regular mount with cleats on back is more expensive or as expensive as matting and framing.

Kirk - high-qualtity substrates like Dibond are very expensive compared to traditional
drymounting and are generally reserved for mounting big color prints, especially high
gloss like Ciba or Fuji Supergloss which are prone to "orangepeel" on paper or fomeboard substrates. This is generally done with a hi-tack acrylic cold mount adhesive - again, a lot more expensive than drymounting and a helluva lot more unforgiving. Very large fiber-based silver prints are a lot easier to wet mount on a
vaccum press if one know correct technique. Once you involve a nonporous plastic
or metal on either surface, the game changes.

[Drew Wiley]

Both Seal and Daige make an excellent wet mount adhesive. This is probably the best
way to mount fiber-based mural-size prints. You don't even need a vacuum press,
although this makes it a little easier. The board must be able to absorb a small amount
of moisture, so no Dibond or Gator. There are high quality mtg boards available for this
which are smoother than conventional fomeboard but still pH neutral paper-faced. Ultraboard and Artcore come to mind. You basically use a closed-cell foam "weenie" roller like painters use for enamels. The quality of the roller is important. Just don't get any adhesive on the face of the print. Cleans up with water. Then you countermount a sheet of something on the back of the board to prevent long-term curling. You could also spray the adhesive. It's permanent, nontoxic, nonstaining, and inexpensive. No health issues like spray contact print adhesives; but the room humidity has to be low enough for consistent drying (a real problem here in coastal fog land!).

[Drew Wiley]

Ok, Bob, now I understand about the platinums. The Dibond was used as a backing for
the sake of registration dimensional stability. Smart idea.

[bob carnie]

Drew

Generally I don't doubt your advice, but are we talking about silver gelatin fibre prints from an enlarger. *wet prints*
I cannot imagine how in the hell this would work. the paper is so curly , it sounds like an incredibly messy , potentially impossible way to mount.
I have a 40x60 hot press for all large murals and am looking for an 4ft x 8ft press as I am moving towards larger prints in 2011 , 40x50 and 4ftx 7ft fibre murals , your method sounds impossible..
sorry to be so doubtful but enquiring minds need to know.

Bob




Both Seal and Daige make an excellent wet mount adhesive. This is probably the best
way to mount fiber-based mural-size prints. You don't even need a vacuum press,
although this makes it a little easier. The board must be able to absorb a small amount
of moisture, so no Dibond or Gator. There are high quality mtg boards available for this
which are smoother than conventional fomeboard but still pH neutral paper-faced. Ultraboard and Artcore come to mind. You basically use a closed-cell foam "weenie" roller like painters use for enamels. The quality of the roller is important. Just don't get any adhesive on the face of the print. Cleans up with water. Then you countermount a sheet of something on the back of the board to prevent long-term curling. You could also spray the adhesive. It's permanent, nontoxic, nonstaining, and inexpensive. No health issues like spray contact print adhesives; but the room humidity has to be low enough for consistent drying (a real problem here in coastal fog land!).

[Drew Wiley]

Bob - wet mounting has been a standard technique for a century. Some framing shops
specialize in it. It is really quite easy once you get the knack for it. But it does carry
the risk of ruining everything with one misplaced splat! Not even remotely as much
trouble or risk as cold mounting with high-pressure rollers, however. In fact, it's a lot easier than laying down Formica, which I have no trouble with personally. Just another option. Drymounting is certainly the most convenient and lowest-risk option for fiber-based photographs, but has its own distinct learning curve. I wouldn't switch if drymounting is already working well for you.

[falth j]

As an aside...

what would Louis Daguerre say about all this… :confused:

[bob carnie]

Well , you learn something every day here , I have never heard of this with fibre based paper , and you are right I will not try it as my methods are working well.


Bob - wet mounting has been a standard technique for a century. Some framing shops
specialize in it. It is really quite easy once you get the knack for it. But it does carry
the risk of ruining everything with one misplaced splat! Not even remotely as much
trouble or risk as cold mounting with high-pressure rollers, however. In fact, it's a lot easier than laying down Formica, which I have no trouble with personally. Just another option. Drymounting is certainly the most convenient and lowest-risk option for fiber-based photographs, but has its own distinct learning curve. I wouldn't switch if drymounting is already working well for you.

[sanking]

Sandy,

The thread height is actually half of .019" :-)

-Leon

Leon,

Thanks. I see what you mean.

Sandy

[sanking]

In fact the method I used to calculate thread height turns out to be totally off base. I assume it would work because a fellow at one of the leading nuts and bolts places in the country told me how to figure thread height, but his advice turned out to be totally wrong. For example, when I did the calculations for a 1-8 stainless steel rod the figures indicated a thread height of 0.0225", which is less than 0.5 mm. When I actually measure the thread height of a 1-8 rod the thread height was 1.8 mm.

So I am back to home plate on how to determine rod thread height. Only way that works for sure is to measure a real rod.

Sandy