Re: My own PVA glue sizing experience (attn: marek + the gum woesagain)
maybe it's a different recipe after all. i don't have any coating problems at all, not even at a 1+1 dilution. at 1+1 there is a little beading action when the emulsion is first applied, but it smoothes out fine, even before i start with the second brush.
i can't get around the problem with the bad adherence of the exposed gum (with my caparol binder size)
it took me while to notice (at first i thought it's the strength of the red layer that overpowers the yellow one), but brushing on another layer on top of an image, brushes off parts of the layer beneath.
it's a dilemma, single layers print absolutely beautiful, but if i can't print multi-layer, it's unusable. i've now checked with different dilutions (1+4 and 1+20) and with exposure times from 1min to 9min (images print fine at about 1:30). a little brushing with a wet brush on a dried print and it comes right off. it sticks a little better at the 1+20 dilution, but not much.
i'm thinking now about diluting the pva with gelatin, to maybe get the best of both worlds... but this would need hardening again and all advantage would be lost. most likely i'll just order the gamblin.
marek, did you ever notice bad adherence with the gamblin size? could you maybe check with a wet brush on a discarded test print? with a higher dilution of the gamblin, if possible?
and to annoy people one more time with my ugly test strips: http://i31.photobucket.com/albums/c367/phritz/1-2.jpg
i finally got the stain with the caparol size too. i'm now sure it's nothing in the material. this only leaves either a combination of various minor influences or humidity.
i don't use a preservative in my gum stock solution, so i keep the bottle in the fridge. sometimes i use it cold, right out of the fridge and i did a test to see whether the temperature has an influence or not. this is one sheet of paper, sized with 1+4 caparol binder, cut in three pieces
. the bottom strip is the "cold gum" mix. the middle one (not beautiful, but stain free) is coated the next day with exactly the same emulsion- i kept it in the closed mixing vessel overnight (also notice the reduced sensitivity). the top strip is a mix applied freshly, the same proportions/ pigment as before.
i'm definitely buying a hygrometer now.
Loris Medici schrieb:
I've tried the a local Caparol product "Fil-fix", which according to