RE: Temperaprint

Hello Pete,

> Great an Egg-tempera-print question at last. the process like all
> dichromated colloid systems has its own little personal problems.

Well there is nothing perfect out there and I've had my fair share
of problems with other processes, but this was the first one I just
couldn't seem to figure out on my own!

> This maybe an indicator that exposure is your problem. Around your
> white box do you have exposed egg emulsion.This would seem to
> indicate that you just have not given enough exposure.

Yes, I have lovely black border around my pictures. I'm just
playing with black monochrome pictures (as I had several tubes of
black liquatex on hand) though I'm looking foward to tri-color in the
future.

> What kind of negatives are you using contone, lith, paper, inkjet,
> imagesetter. Each will give differing times due to the differing
> light absorption of the base.

I've tried oiled paper negatives (made on an inkjet)and I've also
been using peeled RC paper negatives (a process I ironically also
learned about in an older message you sent to this list!). Now
that I think back, I believe the best success I've had, those where
I was able to retain small peices of the image, were with the RC
images. I'm probably too quick to dismiss exposure and am probably
overestimating the sensitivity of the dichromate.

I think I need to better heed what you say below and not be in such
a hurry!

> To get you into the ballpark (where have I heard that expression before ?)
> so to speak.
>
> Make up a mixture of one part of pigment to six parts egg-tempera
> STEM (1+6) coat this onto your Yupo substrate.
>
> Use a foam roller make sure your coat is as smooth and thin as possible.

This is where I believe I may be having my biggest problem. I didn't
actually consider this before. I think I may be using too much paint
as well. The emulsion falls off with the same sort of gummy quality
that acrylic paint peels when it's almost dry.

I've been using more like 1 part paint + 3 parts STEM and considering
I'm pretty liberal with the paint, it probably comes out to more like
1+2.

I believe I may also need to work at getting the coating thinner.

> Expose in direct sunlight the exposure will be in the order of
> one to three minutes for lith, and imagesetter negs however some
> inkjet, contone or paper negs will need more.

I think I will try to aim for overexposure and work my way down,
instead of trying to work my up. At least this way I can rule out
exposure being the problem with getting it to stick or not.

> Wash/develope also using a foam roller in a flat bottom dish containing
> clean water with a small squirt of washing up liquid.Roll gently and you
> will see the unexposed egg dissolve out of the image dont be in a hurry !.

I'll definatly try the roller for developing instead of a brush.
I hadn't actually considered that avenue.

> Don't use brushes until you are firmly in control of the process then they
> can be very useful when using creative scumbling technique.

I think I had gotten it into my head that the brush was an absolute
neccessity for development. I was thinking that the colloid was so thick
it needed more help than gum arabic, for example, to be released from
the paper.

> It is not the eggs I once did some research on eggs and found
> that they are remarkably consistent around the world

I can say, from visual inspection of eggs bought at the supermarket and
eggs bought warmly laid, I could not ascertain any difference in them...lol
Fresh eggs are fresh eggs.

> Yes 12 hours is far to long the process is similar to gum in that it
> also suffers from Dark/continuing reaction this means it slowly fogs
> and becomes turgid in time I do not use my basic (STEM standard emulsion)
> after three hours it gets thrown away

It's good to have a time frame for that and I think 3 hours is reasonable
enough ammount of time. I had been using your article as published in
"Coming Into Focus" and just discovered the version on your website had
some extra information. My main issue had simply been that since I'm
printing small images right now (roughly 4x5) I've been throwing away
quite a bit of STEM after a 1-2 printing sessions. Since it's roughly 1
part sensitizer + 2 parts egg I can mix up smaller ammounts at a time and
not feel so wasteful...lol

> Please get back to me if you need any more assistance
>
> Happy egg-tempera-print

Thank you VERY much for your assistance! I'll probably be back with
more questions eventually, try to bare with me...lol

   -David-

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