Recent content by alecrmyers

Ooh. Fabulous. That would be a step forward. Is the mercaptopurine responsible do you think? Does it work with DEHA?

double post

HEC and CMC: I mix them up in buk a litre at a time in a Kitchenaid blender. The shelf life is long. You should try anaerobic mixing; I'm the last person to want anyone not to try anything - but there are easy ways to give it a go without expensive purchases, to see if it does anything for you...

Mixing in an inert atmosphere is very straightforward. You just need a round flask with two necks, a couple of vacuum adapters and a cylinder of nitrogen or argon at your choice. Do the mixing on a stirplate and flush the cavity above the ingredients through with your choice of inert gas before...

The Dmax and tone both look excellent. As far as detail goes - this process is effectively a contact print from a large format negative. The detail should be absurdly fine (and I have some prints where it is). If the detail isn’t eye-popping then there’s something to investigate.

I put up a small website about this process with a couple of recipes and comments: https://diffusiontransferprinting.info/ Anyone is welcome to send the link to their colleagues or friends.

My reason for not using fixed-out photo paper as the receiver is ideological. If I was going to use a sheet of (expensive) photo paper to make a print, I'd just just develop the negative and make the print the regular way. My goal was make the materials from scratch, or at least from materials...

Really impressive. Really.

Have you tried slowing the roller by hand to see if it improves your print density? What was the result? It seems premature to go to a lot of trouble reengineering the drive when it's so trivially easy to verify if roller speed makes any difference.

Stick you thumb on the rollers to slow them down, and see if it’s beneficial, before you spend on engineering resource.

whats with the weird discontinuity over the doll’s left ear? Did the paper rip? Photo paper at 64ASA is impressive too. I missed that detail.

Excellent progress. The tone is very good.

Just as a matter of historical record, coated Polaroid products were based around metal in silica coatings with hydroquinone/thiosulphate chemistry, and the coaterless ones used a layer of cellulose acetate containing nucleation sites with DEHA/uracil type chemistry.

A lot of people with Polaroid 8x10 processors are going to be beating down your door soon.

I can speak only from my experience, which suggests that viscosity isn't important, except for practical convenience: too loose and the developer runs all over the place; too thick and it doesn't wipe up easily. 2.5-4% CMC seems to work well for me without any obvious differences to the results...