Re: Temperaprint

David,

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

  After exposure, when I'm developing the
> picture, I keep rubbing off the emulsion. I usually just end up with a white
> box where my negative was. I've been rubbing very gently, to the point that
> I'm barely touching the paper

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.

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.

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.

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.

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've tried various brushes from course to
> super soft to no avail.

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

Is there a difference in using Amm or Pot. Dichromates other than
> printing speed or the like? I only ask as I can get the Pot. Dich. locally
> so that's simply for convenience.

Yes there is a four to six times difference in exposure speed. I have found
the Amm Dichromate works fine for my process and it is that much faster.

 I thought maybe there was a problem with the eggs I was using,
> but I've gone so far as to drive out to the "country" and buy freshly laid
> eggs and still have the same problem.

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

  Also, how fast does the egg colloid go
> bad and lose effectiveness? I only ask as I print in the morning and
> evening (before and after work) and was wondering if say, 12 hours would be
> too long to keep it?

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

 I'd move on to something else. Problem is, I love the look of this
> process, even more than gum and figured I'd ask for some assistance before I
> continue any further.

David,

Don't you dare remember it is always the darkest before before the dawn.

Please get back to me if you need any more assistance

Happy egg-tempera-print

Pete

http://www.alternativephotography.com/peter_fredrick.html
http://www.books.i12.com/parlour/index.html
http://www.books.i12.com/parlour/tempera.html
Received on Wed Jan 28 07:03:53 2004