Coating Pt/Pd prints: results to-date

[paulr]

"I diulte the varnish, and polish lightly in-between coats, as is done with shellac on furniture. Ideally, lots of very thin coats."

Do you use a brush? If so, what kind works best for you?

And Annie writes .... "Dissolve by volume 1 part rabbit skin glue or hide glue (my apologies to all the bunnies) ..."

Just be aware that virtually all natural coatings (including authentic pine oil varnish) will yellow significantly as they age. One of the advantages of some of these acrylic products, like the Golden polymer varnishes, is their stability and resistance to yellowing.

livick.com has some pretty thorough artificial aging tests done on a few of these products, including different combinations of fixative and varnish. He's dealing with inkjet prints, not platinum prints, so lightfastness is a major part of his tests. It's still relevent to platinum prints though, because of lighfastness/yellowing issues of the coatings themselves.

As far as lightfastness of Platinum prints, I haven't seen any real studies done on this. I would expect the image itself to be stable, but some of the natural finish papers are probably susceptible to bleaching from UV exposure. I did one very informal test that showed this might be an issue. It's possible that some of these UV blocking varnishes could help.

Obviously, not hanging prints that you like in the window will also help.

[Annie M.]

One of the advantages of the rabbit skin glue is that it is archival and can be removed without harming the print..... employment opportunities for museum archivists of the future!

[Ken Lee]

I have been using a Princeton 1.5 inch "Flat Wash" brush - but there are others which are probably much better.

I just went to the art supply store and when I bought the varnish, I asked them for a brush to go with it. I haven't really explored the effects of brushes - other than to note that the cheap ones lose their hairs and leave streaks.

I have not tried spray application, as I would prefer to avoid the health hazards if possible - and hope not to spend money on a ventilation hood.

Rather than applying one heavy coat, it is best to apply many thin coats, and reduce any imperfections between each one. This requires time and patience.

When we consider the effort and time required to prepare Pt/Pd paper - and that time is money - I'm starting to realize that perhaps those AZO people ain't so dumb after all. ;-)

[Nicholas Whitman]

Thought I'd revive this old thread as it came up in a search regarding post processing of platinotypes.

Also check out the link in post #6. One of the coolest treasures I've ever stumbled upon on the www!
aic.stanford.edu/jaic/articles/jaic34-01-001_indx.html

I've printed platinum for many years and know is characteristics for better and for worse. The difference in dry down is always a factor in all wet processes but it can be acute with platinum. So you compensate , i.e. the print should look too light when wet. But sometimes even in a properly exposed print the shadows will be "smokey". A salt print will have the same effect - so it is more a function of the paper than the metal in the image. But the lower values can be brought to the fore with post processing.

I've been experimenting with some readily available products and thought I'd post these results.

Years ago I used a gelatin formula (knox gelatin with a preservative and photoflow) from Booth & Weinstein's Collection, Use & Care of Historic Photographs. Worked ok but was messy and very temperature sensitive. Is archival and reversible though.

Spray on Krylon acrylic. Makes the paper bullet proof but no improvement in the blacks - dead end.

Water based varnish - Minwax polycrylic clear semi gloss. Got this stuff to try coating canvas images. Adds durability but difficult to get an even coating. Tried various dilutions and got better results with a build up and sponge brushes. but abandoned it for canvas.

The other day I coated some platinotypes - just to see. Results showed promise but I had poor coating results and puckering. I used a sponge brush. Figured the solution to puckering was to do the same thing to both sides of the sheet - so I immersed the print in a tray non-diluted polycrylic and allowed to drip dry. The result was a really rich print, wonderful low value separation and pearly whites. Not a platinum "feel" but a super rich gel/silver.

Aside from the fact that non-reversible treatments make conservators crazy there could be potential here. I think a diluted solution will be worth a try. Also I might try immersion and the pushing the excess off with a glass rod - like some do to coat emulsion.

Just thought I put this up and ask what you other workers have had luck with?

Thanks,
Nick
www.nwphoto.com

[davidjohnlotto]

Renaissance wax works very well on all papers for that "wet look" ...even handmade Japanese papers. I haven't found varnish necessary.

[patrickjames]

I think I talked to David John about this several years ago. I found that buffing the wax is what does the trick for me. I don't do it to platinum prints though, but when I use wax I buff it with a hand held shoe buffer from Sharper Image I picked up for a few bucks. I used to buff them by hand and it gave me a good workout, but I ruined a lot of prints with creases. I don't have that problem with the shoe buffer. One of these days I will buy an electric one.

[Ken Lee]

Thanks for your interest.

I have put my efforts aside for the time being, and focused on improving my vision instead.

I hope to return to the process some day, and perhaps then there will be an agreeable solution.

[Nicholas Whitman]

I am wary of adding anything organ to an image as it is food for some life form. There are of course a lot of gelatin based images out there, they have preservatives added and don't support mold under reasonable conditions.

It would seem an inorganic acrylic coating would be immune from rot - though admittably not reversible. If the image is pure metal pt/pd and the paper is 100% acid free rag then sealed in an inert medium what could go wrong (within reason - not cooking in a sunny window)?

[Attack]

OK... I've had a chance to dig through my old 'swatches' ....

To obtain a luster finish comparable to an air dried silver glossy fibre based paper such as Agfa Classic... Dissolve by volume 1 part rabbit skin glue or hide glue (my apologies to all the bunnies) to 6 parts water in a double boiler or over very low heat. DO NOT BOIL. This is a thicker mixture than the usual preparation for canvas prep in painting etc. While the mixture is hot apply it to your paper... as this starts to goo up quite quickly I have found the best method is to attach my Pt print to a board with butcher tape around the outside edge (if you wish to maintain the dekel edge you will have to figure out a different method as I cut the tape off at the end of the process). I use a squeegee to apply the hot glue in one pass over the image.... if you use a brush I assume any marks will flow back into an even surface due to the viscosity of the mixture. You can let the print air dry or use a dryer if you wish. When dry the print is a bit stiff I just give it a run over the edge of the table as the finish is a little plyable and will not crack.

Now... this finish will warm the image and the paper slightly... so no pure bright whites... however the dry down effect is gone... absolutely gone. Another concern may be the method of mounting... I do not use a hot press so I have no idea how this would effect the coating. The test swatches I have here are on Cranes and Kodak PX-3001 (emulsion removed) so I have no idea how the glue would adapt to a more textured paper... you may have to adjust your dilutions according to the penetrability of your paper

This coating once dry will also accept varnishes and you can take it to high gloss if you are inclined to do so.... which reminds me it wasn't varnish over wax as I said in my post above... it was a 'fat' wax over a 'lean' wax (such as the wax mediums & the Marshall's oil dryer) I found the paper experienced less distressing when the wax gels were used prior to the crystalline.

Anyway... keep up the good work and let us know if you find your magic coating!!

Cheers Annie

Hello to all! Who ever tried Annie's recipe?
Or did new varnish recipes for Pt/Pd appear?

[faberryman]

I'm not letting wax or varnish anywhere near my platinum palladium prints. Why would I want to make them look like something other than what they are?