U of S | Mailing List Archive | alt-photo-process-l | Re: My own PVA glue sizing experience (attn: marek + the gum woesagain

Re: My own PVA glue sizing experience (attn: marek + the gum woesagain)

two more things i forgot to add.:
i've noticed that the strength of the pva-size affects the thickness of the emulsion layer. with a 1+4 size the emulsion is noticeably thinner than the same emulsion on a 1+20 size. most likely because with the thinner size, there are more paper fibers for the emulsion to adhere to.
and the caparol binder size on (unprimed) canvas didn't work at all. not even the brightest highlights came off.
caparol 1+4 on primed canvas and wood (a layer of white acrylic primer beneath) did print fine, but the exposed gum had nothing to adhere to and washed off completely. the situation was a little better on the canvas than on the wood.
maybe this is interesting to someone.


phritz phantom schrieb:
that's why i asked you if you could check for the adherence. thanks for that btw.
i will order some of the gamblin next week, to try next.

i know the strips aren't good, but if the conditions stay like in the second example (the stainfree one on caparol i just sent again), that's something i can work with and improve. btw there is also no curve applied at all, so it's supposed to be detail in only two or three lines of the scale. if the outcome is stained and/or inversed like that, there is no real point to trying to make fine adjustments.
you'd have to take my word for that, but the conditions of the two test strips were identical (at least concening ingredients and workflow and as far as i can tell). this sounds pretty stupid, but the last time i got the stain (two weeks ago), it was rainy weather outside and yesterday it was rainy again. so maybe it really has something to do with humidity...


Loris Medici schrieb:
Hi Phritz, my PVAc glue is a Caparol product too. Just a different
type of PVAc (and/or different formulation)...

As I said before, PVAc glue/sizing is a very vague description;
molecular weight, hydrolization ratio, solution strength and extra
additives all are definitive. And unfortunately no manufacturer is
stating these (= the exact formulation) in their product information

Try another one if this is not working for you.

I must insist something's wrong with your coating solutions; none of
your posted step tablet prints were successful in my criteria...


2009/10/23 phritz phantom <phritz-phantom@web.de>:

it's good to hear that your pva works better than the caparol. so there is
hope with the substance.