From: Andre Fuhrmann (Andre.Fuhrmann@uni-konstanz.de)
Date: 06/18/01-02:42:45 AM Z
Over the weekend I put in a POP-printing session and ran across a
problem as follows.
1st SETUP:
(A) Salty gelatine according to Liam Lawless's recipe in PF. [But
instead of salt + ammonium citrate I used just 5g plain salt per
200ml gelatine emulsion. This worked perfectly last time round.] The
emulsion was about half a year old, thymol added and stored in the
fridge -- smelled alright. Gently heated in a microwave to about 40
C.
(B) Silver nitrate, saturated solution (about =< 15%).
Paper: Arche Aquarelle.
Coated twice with glas rod; dried 30 minutes; exposed to UV: very
little happened (just a purple hue )-:
Thought the gelatine might had gone bad (but how??). So ...
2nd SETUP:
(A) I prepared a new batch of gelatine. Heated it gently the next
day in a water bath and added
(B) as before
Now I first tested (A+B) by dropping a bit on a piece of paper and
exposed it to the sun (still wet): it darkened within a matter of
seconds. Next: single coating; drying 1 hour; exposure to UV: same
effect as the day before )-:
3rd SETUP
I didn't want to throw away all the coated paper. So I put a single
layer of silver nitrate (about 6%) on top. Drying and exposure as
before: worked perfectly (-:
Of course, the 3rd setup is sort of midway between traditional salt
printing and POP. But I wanted the latter. Any suggestions as to
what might have gone wrong?
André
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