I have occasionally had a quite odd problem with Gum prints. Apparently randomly and with any layer I will get something that looks like a water stain on paper, that is there is no distortion of line or color within the blotch like shape but the border is outlined with a thin line in the color of the layer. This leads to a "Hail Mary" session with spotting brushes on the wet print as it develops and the retouching usually fails miserably. I have attached a detail from a work print that shows the sort of line I am describing. The last print I posted on the Hand Coated Wet Print Gallery had this problem but I was actually able to retouch it out.
Anyway if anyone has any idea why a problem like this would occur, please let me know.
I have occasionally had a quite odd problem with Gum prints. Apparently randomly and with any layer I will get something that looks like a water stain on paper, that is there is no distortion of line or color within the blotch like shape but the border is outlined with a thin line in the color of the layer. This leads to a "Hail Mary" session with spotting brushes on the wet print as it develops and the retouching usually fails miserably. I have attached a detail from a work print that shows the sort of line I am describing. The last print I posted on the Hand Coated Wet Print Gallery had this problem but I was actually able to retouch it out.
Anyway if anyone has any idea why a problem like this would occur, please let me know.
What paper are you using is my first question? Is the paper sized? Has it been pre-shrunk? We need more details.
The paper is Fabriano Artistico Hot Press sized with Glutaraldhyde.
I am happy to provide any other details.
Okay I size FAEW with glut. Tell me how you are doing that? From what I can see you's got a problem with the gelatin sizing or the internal sizing of the paper, but maybe not. Are you pre-soaking your paper? If so are you using warm or hot water?
How large is this defect? From looking at your image in the gallery I don't have a sense of the problem in the image (am I looking at the correct image?). Could you post a direct link to the gallery image?
Okay I size FAEW with glut. Tell me how you are doing that? From what I can see you's got a problem with the gelatin sizing or the internal sizing of the paper, but maybe not. Are you pre-soaking your paper? If so are you using warm or hot water?
How large is this defect? From looking at your image in the gallery I don't have a sense of the problem in the image (am I looking at the correct image?). Could you post a direct link to the gallery image?
Thanks,
Don
Hi Don,
I size with 50ml gelatin that has 2.5ml of absolute alcohol and .3ml if 2.5% glut. I apply it with a foam brush trying not to overcoat. Sadly the picture I posted doesn't give a very good indication of the problem. The size is usually aprox the radius of a lemon or orange but more irregular. Here's a direct link (I hope) to the gallery image. http://www.hybridphoto.com/gallery/s....php?i=809&c=8
I managed to nearly eliminate the problem from the gallery image. With that image the problem occurred on the fifth layer (1-cyanotype, 2-indian yellow, 3-deep scarlet, 4 payne's grey to highlights, 5-payne's grey to the shadows. The problem occurred following the application of the fifth layer appearing in the clear white areas of the print or lightly tinted areas.
It is quite odd. If my information is not giving you the information you need, I will wait until the problem recurs and shoot a digital picture of the image in the developing water.
I size with 50ml gelatin that has 2.5ml of absolute alcohol and .3ml if 2.5% glut.
This makes no sense. What is the percentage of gelatin concentration? What is absolute alcohol? Vodka? If your gelatin concentration is 3% then your glut dilution is in line with what I use. I assume the Vodka is to reduce the sparkles.
I apply it with a foam brush trying not to overcoat.
That's sort of irrelevant - over coating that is. I size entire 22x30 inch parent sheets 10 to 20 at a time. It's more productive to do that. And I also probably put a thicker coating of gelatin on the paper than you do. For a 22x30 inch sheet I size with 38ml of gelatin, which is more than enough gelatin. The gelatin is also quite warm, between 135-140F.
The problem occurred following the application of the fifth layer appearing in the clear white areas of the print or lightly tinted areas.
If this is the case then you probably have a problem with the gum/pigment coating or a breakdown of the gelatin. Also 5 layers is really pushing the envelope IME. That many development cycles on sized paper can reduce the effectiveness of the sizing.
This makes no sense. What is the percentage of gelatin concentration? What is absolute alcohol? Vodka? If your gelatin concentration is 3% then your glut dilution is in line with what I use. I assume the Vodka is to reduce the sparkles.
That's sort of irrelevant - over coating that is. I size entire 22x30 inch parent sheets 10 to 20 at a time. It's more productive to do that. And I also probably put a thicker coating of gelatin on the paper than you do. For a 22x30 inch sheet I size with 38ml of gelatin, which is more than enough gelatin. The gelatin is also quite warm, between 135-140F.
If this is the case then you probably have a problem with the gum/pigment coating or a breakdown of the gelatin. Also 5 layers is really pushing the envelope IME. That many development cycles on sized paper can reduce the effectiveness of the sizing.
Hi Don,
Yes the gelatin is 3%, sorry about not including that. The alcohol is reagent grade 200 proof lab alcohol. We can't get the high proof Everclear in CA. The 50 ml of 3% gelatin is nearly twice what I need to size 5, 8x10 image spaces on 11x14 Fabriano. In this there may be a clue I may be undersizing in response to reading that oversizing can create problems (per Livick). And yes, I heat the gelatin mix to 160°F before taking it out to the studio to do the coating.
I try for three layers with tricolor and monochrome and usually that works. However this print needed additional correction, hence the additional layers of payne's grey.
Here's another possibility: The final layer of payne's grey was mixed to tint the shadows, so it was: .9gm paint, 4.5 ml potassium dichromate and 7.5 ml gum and a short exposure. That makes a really thick layer and perhaps the thickness combined with the fact it was layer five could have contributed to the problem. (Note-I weigh the paint but do not use the same measurements for each color. Relative weights are established to match the tinting strength of various pigments.)
If you have any suggestions I will greatly appreciate them. If not, I shall keep observing and try to return with more detailed information and better photographs of the problem areas.
I heat the gelatin mix to 160°F before taking it out to the studio to do the coating.
That's too hot for gelatin. I keep the gelatin hot and cover the gelatin mixing vessel with a piece of glass to prevent evaporation.
I try for three layers with tricolor and monochrome and usually that works. However this print needed additional correction, hence the additional layers of payne's grey.
How long do you develop?
Here's another possibility: The final layer of payne's grey was mixed to tint the shadows, so it was: .9gm paint, 4.5 ml potassium dichromate and 7.5 ml gum and a short exposure. That makes a really thick layer and perhaps the thickness combined with the fact it was layer five could have contributed to the problem.
Avoid thick layers of gum.
(Note-I weigh the paint but do not use the same measurements for each color. Relative weights are established to match the tinting strength of various pigments.)
Right.
If you have any suggestions I will greatly appreciate them. If not, I shall keep observing and try to return with more detailed information and better photographs of the problem areas.
Many Thanks!!
Keep printing you are doing pretty good, IMO - nothing is ever perfect. What strength is your dichromate? Your image looks a bit contrasty. Have you tried AD? I use about 15% AD. I could probably reduce that but I hate to recalibrate.
I don't size at all and I can get 5 layers with no staining. Normally I like to get it done in 3, but my last one took 2 more layers, one each in the magenta and cyan layers. Not my best print, but pretty decent.
I like Fabriano as well, and really like the soft press which seems to be sized a bit more and stiffer than the regular Artistico EW hot press. There's a bit of a canvas texture to it which may not be to everyone's liking.
I figure if Keith Taylor can mount on aluminum with no sizing, you can do the same thing even if you don't mount...but you may have to preshrink depending on the size of your print. If I preshrink it's only for 5 minutes in room temperature water, which for Fabriano seems to do the trick.
But everyone's experience is so variable with gum that it's hard to nail down or duplicate another person's workflow...
I don't size at all and I can get 5 layers with no staining. Normally I like to get it done in 3, but my last one took 2 more layers, one each in the magenta and cyan layers. Not my best print, but pretty decent.
That's not the issue here specifically. Jon is sizing and he maybe having a sizing issue.
I like Fabriano as well, and really like the soft press which seems to be sized a bit more and stiffer than the regular Artistico EW hot press. There's a bit of a canvas texture to it which may not be to everyone's liking.
I preshrink my papers much more extensively but with cool water and parent sized sheets. I don't have a problem with internal sizing. I also develop my prints much longer than you do Paul. And if you do some physical development it's nice to work on a sized paper.
I figure if Keith Taylor can mount on aluminum with no sizing, you can do the same thing even if you don't mount...but you may have to preshrink depending on the size of your print. If I preshrink it's only for 5 minutes in room temperature water, which for Fabriano seems to do the trick.
You live in a very arid environment so I wouldn't count on your pre-shrink method to be valid for those who do not. But imobolizing the paper is certainly away to avoid that.
But everyone's experience is so variable with gum that it's hard to nail down or duplicate another person's workflow...
I'm not sold on the notion of no sizing.
Don, maybe you've seen these before so I apologize if I'm repeating myself.
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Originally Posted by Jon Harwood 
