Getting a good dmax with Gum Bichromate

AltGirl · Mar 31, 2011

I am struggling to create a gum print with a good dmax. Yet as I print more black layers, the image just gets muddy looking and loses definition. I am wondering if by printing a blue layer first, the black would look better.

Does any one have any suggestions? Would printing a Cyanotype layer work or is there a really nice blue pigment that I could mix into my black or lay down first?

I would appreciate any suggestions.

Loris Medici · Apr 1, 2011

Altgirl, IME, gum over cyanotype has definitely good definition and a higher potential of strong shadows. If you want pure gum images, then try pthalo-blue. (PB 15:3 or other PB 15:x variants - I personally prefer the greenish PB 15:3...) Which black do you use BTW?

PVia · Apr 1, 2011

Also, check your sensitizer ratios. In later layers, reduce the dichromate in relation to the gum to get more contrast. The color will go the shadows only, without interfering too much with the rest of the tonalities.

And make sure your negative is giving you enough separation (contrast) to place the pigment where you want it to go.

There are so many variables to consider...

hx processes · Apr 1, 2011

try mixing some blue and black together, better dmax than lamp black alone.

AltGirl · May 30, 2011

Thank you for all of these ideas. I have been trying them out and I am slowly getting some great results!

Bruce · May 31, 2011

ALTGirl

Go to the Unblinking Eye web site and look for the article by Sam Wang on "Tri Color Gum With Cyanotype". He does use cyanotype as his first layer.

Are you using just one negative?

AltGirl · May 31, 2011

I am working with three different negatives - highs, lows and mid tones - in order to be able to capture the shadow detail. I have read S. Wang's article on Tri-color Gum and it has proven to be very useful.
I am beginning to wonder if gum is one of those processes that works best when teamed with another printing method (i.e. cyantotype or palladium).

And I am also going to mix some blue into my black next time I am working with gum. Great idea! Thanks for the head up on which blue combo to try out.

PVia · Jun 1, 2011

AltGirl, are you trying to do one layer prints or multi-layer?

AltGirl · Jun 1, 2011

multiple layers - I have successfully done 2 but now its getting concentrations/timing right to get to that critical 3rd layer.

PVia · Jun 2, 2011

There are so many variables...dichromate concentration, pigment ratio and amounts, the individual negatives. It's endless. All I can say is make tons of prints, always print, become obsessed...and keep a journal of notes with every permutation you try. Be surprised, welcome the 'angel of uncertainty' in your work, behold the happy accident. It took me a year before I felt I had a handle on the process and was producing prints I was proud to show.

AltGirl · Jun 5, 2011

Thanks for the suggestion. I am starting to realize that there is a world of information out there.
BTW, what pigment brand do you use... I am tossed between Windsor Newton professional and Daniel Smith. I have also heard good things about Graham. Which is the best or is it more a question of pigment content?

PVia · Jun 6, 2011

I use Daniel Smith and a few Sennelier pigments, but I really believe that any good professional pigment will do a great job, having more pigment and less filler.

Getting a good dmax with Gum Bichromate

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