Questions re vandyke processing

[CharlesWest]

You're trying to compare apples to oranges with silver gelatin and Van Dyke negative comparisons. Stop trying. You need two different negatives. There's something about emulsion curves you're not understanding. Every emulsion with every paper has a different characteristic curve. I need three negatives for printing silver gelatin, Van Dyke, and cyanotype, and yet another for pt/pd, but you can often get away using the same negative for pt/pd that you use for Van Dyke.

[D. Bryant]

(Since selenium toner is 1/3 rapid fixer!! you almost don't need to fix at all, but I do anyway for consistency.)

Ah, what kind of fixer do you use?

Thanks,

Don

[CharlesWest]

Sodium thiosulfate crystals. 30g per 1000ml for a 3% solution. Two baths. Change A after ten prints with B, and mix up a new B.

http://www.google.com/search?client=...4607d52d82d8c1

Please review John Barnier's book:
http://www.google.com/products/catal...d=0CDsQ8wIwAA#

and Christopher Jame's book:
http://www.christopherjames-studio.c...okreviews.html

I'm only parroting back information I've used from those two books. Read carefully, and about all processes, though. Sometimes, you can find a sentence in another process that'll save the day for what you're currently doing.

I can't seem to edit my first post anymore, but, you're going to have a heck of a time getting decent d-Max without humidifying the paper first, or using two coats.
You can store Van Dyke paper, but then you want to dry it out best as possible. Just be sure to rehydrate before printing.
I've only been able to store cyanotype paper for two or three days before chemical fog sets in. Which, can also be useful! And, Bienfang 360 stores much better than any other paper already coated.

[D. Bryant]

I'm only parroting back information I've used from those two books.

Thanks Charles.

Don Bryant

[reyno bundit]

i use a second coat of sensitizer , allow to dry between coats, a drop or two of dichromate helps with contrast ,dont use too much though.

negs are over developed to hold highlights double time at least.

also a double coat of gelatin, i soak in 4% gel + 1% of 3% dichromate solution, then dry followed by a brush coat of the same gel + dichro
then dry and tan in u.v light.
then a 10 min soak in clearing agent metabisulphate
30 min wash and dry

not quick but gives a nice look

[D. Bryant]

also a double coat of gelatin, i soak in 4% gel + 1% of 3% dichromate solution, then dry followed by a brush coat of the same gel + dichro
then dry and tan in u.v light.

What is the purpose of this step?

Thanks,

Don

[reyno bundit]

well i use it for carbon rag support, so i thought id give it a go with VD , trying to get the gel to sit higher on the paper and to get a smoother surface.

it worked increased sharpness deeper tones and a nice sheen.

i am in the testing stage in doing the same with albumen for VD

hope this helps

Reyno

[D. Bryant]

well i use it for carbon rag support, so i thought id give it a go with VD , trying to get the gel to sit higher on the paper and to get a smoother surface.

it worked increased sharpness deeper tones and a nice sheen.

i am in the testing stage in doing the same with albumen for VD

hope this helps

Reyno

Okay so you are using the dichromate + UV to harden the gelatin, I understand now.

So are you putting the gelatin on after the VDB exposure or coating the VDB sensitizer over the gelatin layer?

Thanks,

Don

[reyno bundit]

hi

im treating the paper in advance of the vd sensitiser

i soak to saturate the paper ,dry ,then coat with a quality smooth 1 inch paste brush to get a reasonably heavy even top coat ,dry once more and expose for 15 min in a u.v burner.

10 min soak in metabisulphate to clear the dichro, wash for 30 min and dry.

it can help at this point to dry flat using watercolour tape on glass.

then you have a nice hardened layer that resists brush sensitisation and of course temp if applicable

i am also going to try multi layer coats using u.v in between coatings to increase gel coating stability
a bit like albumen multi layers without the cracking (fingers crossed)

this tech is great when using wood pulp based art paper as it resists the fibre swelling that normally rules out this paper choice

its fun experimenting

Reyno