Gum bichromate over pt/pd question ....

scootermm

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Ive been doing a fairly good amount of gum over pt/pds the last few months (thanks to Clay for his informal intro to it)
I usually dont start technical question threads as 99% of the time theres an existing thread about whatever it is that Im asking. In this case, I couldnt find anything in the forum in regards to this.
My question, whats the archival nature of Gum Over pt/pds? Does the Gum Bichromate layer hurt the inherent archival nature of palladium prints? (as Ive read in more than a few counts of the longevity claims of pt/pd prints - even seen first hand a few platinum prints that are 100+ yrs old) Or does is add to its archival nature? or just not effect it at all.

Not something Im really worried about ... as I imagine my growing stack of prints will sit in a draw in some desolate house long after Ive left this earth. But curiosity sparked the thought in my head. Along with a question a fellow photographer asked me about the Gum over palladiums Ive been doing as of late. I sat coating two prints with their 3rd gum layers last night and was again curious about this. (posted one of them in the gallery if you are curious

thanks in advance.
 

Jorge

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Dont worry, gum arabic is very stable and should not lower the keeping properties of your prints. Being an organic compound it could be susceptible to fungal growth, pretty much like an Albumen print or a sized salt print. But these cases are rare and happen mostly with poorly kept prints in humid enviroments.
 

Kerik

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I agree with Jorge (glad to see you're getting back on your feet). If anything, there may be some slight fading of your pigments over time, but this will have minimal effect on the overall look of the print. The gelatin and gum layers may provide some additional protection of the pt/pd layer from the environment.
 

Michael Mutmansky

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The pigment is the biggest worry. As long as you use lightfast pigments, you shouldn't see any problems in a reasonable exposure situation.

I tested a combination gume bichromate and palladium print for lightfastness over about a year and a half, putting half of it in a south-facing window. I could detect no difference in the gum or PD layers, and no yellowing of the liquitex that I normally use to seal the gum layers. The only change I could detect was a slight bleaching of the paper.

So, use lightfast pigments, properly clear the dichromate and you should have no problems with the gum layers.


---Michael
 

Jeremy

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Michael Mutmansky said:
yellowing of the liquitex that I normally use to seal the gum layers
Click to expand...

Michael, can you explain more of this liquitex sealing you do?
 

Michael Mutmansky

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Jeremy,

I have found that the gum layers can sometimes be a bit fragile and possibly prone to abrasion from handling. The liquitex is basically a PVA glue product that is used to seal acrylic paintings. I cut it with water 1:7 about, and dip the prints in the tray for abour 30 seconds and then hang until mostly dry, and then put on a screen to dry completely.

I figure it does two things. It helps even out the gloss differential between highlights and shadow in the gum, and it also acts like a binder to hold the gum together and make it less likely to flake with handling.

It's not necessary to do this step, but it seems to produce a more consistant surface quality for the print, and increases the dmax a little as well on a straight pd print. Since it seems to test out stable, I don't think there is a downside.


---Michael
 

Jeremy

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Thanks, Michael, I'll have to look into getting some liquitex and trying this out.
 
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scootermm

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Learn something new everyday.
I have a bunch of that stuff for my paintings... new use.

Thanks all for the information (both about the liquitex and the inquiry on archival nature)
 

Michael Mutmansky

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Jeremy and scooter,

I recommens trying various dilutions of the liquitex. I tried everything from straight to 1:11 and originally settled on 1:7, but more recently I have shifted to 1:9.

The lower dilution, the more gloss the paper picks up. less than 1:4 and the stuff is too thick to be dipping, and will leave a fairly thick coat on the paper.

At that point it's personal preference.

I use the gloss varnish medium, if I remember the name correctly. There's also a matte medium, but I haven't tried it. I doubt there will be much difference at high dilution.


---Michael
 
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photomc

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Michael, Thank you for the information. A couple of more questions if you don't mind..one is it Liquitex Gloss Varnish? And would this be a good treatment for a traditional Palldium print as well, to give it just a bit of gloss? I know in the past it was dicussed here that one could use wax and there was some discussion about coating a print with albument as well.

TIA for your time.
 

Michael Mutmansky

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Gloss Varnish Medium. I think the Matte Medium willl work as well, but haven't tried it.

I have tried it on a PD print, but I like the look of a waxed print better. You could do anywhere from 1:4 or so to 1:11 depending on how much gloss you want. However, waxing takes considerable time and some skill, so that is not for everyone.

It did occur to me to try a dip in the liquitex and then wax after. The liquitex may help encapsulate the paper fibers, which could make the waxing a lot easier. I haven't tried it though. I would be thinking of maybe 1:11 for that.


---Michael
 

photomc

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Thanks Michael, will have to pick some up and give it a try...will start with the 1:11 dil.
 
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scootermm

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just a heads up for those in the Continental US and who happen to do either gum printing or gumover printing.

I went by Hobby Lobby yesterday they are having a 33% sale for all paints. Including watercolor pigments. I started doing gum bichromate over pt/pd with the Grumbacher watercolor pigments, I noticed some staining with many color so I decided to replace my pigments with the higher quality Winsor&Newton Artist's Watercolor pigments. Managed to get nearly 12 different 5ml tubes for just over $50 (not bad considering that even at discount art stores the 5ml tubes are roughly $5).

Wanted to pass on the heads up and savings possibility. The sale is apparently going on till this coming saturday (22 July).
 

Michael Mutmansky

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Scooter,

I have one word for you...

Daniel Smith

OK, that's two words. They make a great line of watercolor paints and their prices are the best around. All paints made in Seattle. The also do a free shipping and free paint offer if you buy a certain amount, which I seem to never have a problem meeting.

WN is great paint, but the cost can be a bit much, especially in retail situations. The exchange rate isn't helping much, either.


---Michael
 

donbga

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I would encourage anyone that is doing gum or gum overs to also consider M. Graham brand of water color pigments. M. Graham pigments are nicely priced and can be found discounted here.

http://www.shoptheartstore.com/prod...15&topCat=CA10DC26-FEF2-42B5-BC5A5D7AFBDD7051

M. Graham doesn't produce as many convenience colors as Daniel Smith or Winsor Newton but certainly have equal quality as DS & WN.

The Daniel Smith and WN pigments that I've used have worked great so if you like those stick with them.


 

Michael Mutmansky

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Don,

M Graham paints are great as well from the reports I've heard. I have a few tubes here to do trials with, but haven't done so yet.

Both of these companies make very high quality, high pigment load paints with pure pigments, as long as you select the right colors. There are many blends in the DS list, but there are a number of pure pigment paints as well. Both are also USA made, so a bit less subject to the perils of international exchange rates.

One thing that is interesting is that you won't get the same color on the print from the same 'color' from two different manufacturers. I recently did a comparison between a WN burnt umber and the DS version. the WN has more red undertones to it, if I recall correctly. Most colors are pretty close across the manufacturers, but one color seems to have little consistancy from manufacturer to manufacturer; raw umber.


---Michael
 
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scootermm

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thanks for the info Don and Michael

have another one for you who are more experienced.

are any of these colors to be avoided because of staining or just not being conducive to gum over printing?
These are the colors I purchased:
Terre Verte
Olive Green
Green Gold
Burnt Umber
Burnt Sienna
Indian Red
Perylene Maroon
yellow ochre
naples yellow
new gamboge
cobalt blue
cerulean blue
nuetral tint
ivory black

all are winsor & newton
 

Kerik

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Matt,
Go here to the rather funky W&N website. Click "Exit" on the floating site preview thingy. The, click on "Water Colours" then "Artists Water Colors" then the vertical tab on the left that says "Colour Chart". This is a PDF that will give you general info about their pigments' permanence, transparency and staining characteristics. This chart is also often available for free at stores that sell their paints. Schminke (one of my personal fave brands) makes a fantastic catalog describing thier pigments in much more detail.
 
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scootermm

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Kerik said:
Matt,
Go here to the rather funky W&N website.
Click to expand...

funky website is right.
I would never have found that if you hadnt explained it. I searched for it and couldnt find the info before I posted this. Thanks kerik.
 

donbga

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FWIW,

I've never had staining doing gum overs (up to 3 layers) with these colors by WN:

Green Gold
Burnt Umber
Burnt Sienna
Perylene Maroon
Indian Yellow

With M. Graham:

Burnt Umber
Burnt Sienna
Raw Sienna
new gamboge
cobalt blue
Alzarin Crimson
Q. Violet
Sepia
Ultramarine Blue

But with higher pigment loads (much more than you are probably using for gum overs) certain colors seem prone to staining with strait gum prints. Particulary the violets, ivory black and some reds.

What doesn't stain for me may cause staining for you (or vice versa) due to different methods of sizing, esposure times, and dichromate loads.
 
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