Re: My own PVA glue sizing experience (attn: marek + the gum woesagain)
Hi Phritz, I checked again with a wet hard bristle brush and no gum was lifted until I finally physically damaged the surface. (I brushed very long time and very hard.) Conclusion, my version of PVAc glue size is perfectly fine in that sense. Very tough, very durable and keeps the exposed/developed layer onto itself. BTW, it's not a good idea to keep the coating solution (gum/pigment + dichromate) for a day. You'll get "dark effect". Just mix enough for immediate use. I'll repeat that your coating solutions seems to be very high in pigment load; that's definitely not a coating solution to expose/develop in the normal way, to my eyes. I'd use that much pigment only if I plan bleach development... Regards, Loris. 2009/10/23 phritz phantom <phritz-phantom@web.de>: > hi loris, > 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. > > but... > 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 > > ... > > ... > 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.
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