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

[Paul Viapiano <viapiano@pacbell.net>]

Phritz...

I agree with Loris...

I've found that black and blues in general can stain more easily, and 
especially when they are too concentrated. For example, when printing with 
Ivory Black, I got staining at 1 gram pigment / 2 ml gum, but it worked 
perfectly when increasing the gum to 4 ml.

All pigment brands are different, I am told, so you'll have to find the 
sweet spot for you.




----- Original Message ----- 
From: "Loris Medici" <mail@loris.medici.name>
To: <alt-photo-process-l@usask.ca>
Sent: Friday, October 23, 2009 11:39 AM
Subject: 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.