Digital BW, The Print

Viruses (organic) hang onto paper for a very long time.
On Aug 27, 2012 3:47 AM, "Ernst Dinkla" <e.dinkla@...> wrote:

> **
>
>
> On 08/25/2012 09:38 PM, ClaytonJ wrote:
> > Hello Ernst,
> >
> > > There is now a discussion about Museo Silver Rag on the LL forum.
> >
> > Thanks, I'll have a look.
> >
> > >Is the yellowing happening more on the coating side or more on the
> > paper base?
> >
> > I don't have any sort of instrument to measure the color or intensity,
> > but to my eye the yellowing is equal on the back uncoated side. It
> > occurs on all four edges equally. As for intensity, it is not bright
> > yellow (it doesn't look at all like the bright chemical yellowing we
> > used to see on H. Photo Rag, for example), but is rather faint, but
> > distinct. The hue is yellow, not brownish.
> >
> > >Did it transfer to the papers directly in contact with the MSR?
> >
> > I don't think so, I checked the others again. I don't know which prints
> > were the ones in direct contact, but none of them have yellowing like
> > these five. Some are dirty and have some odd stain spots (one looks like
> > something was spilled on it), but nothing like the even 4-border effect
> > of these five. When I found the stack I stopped work and sat down to
> > examine the prints, which brought back a lot of memories. The stack was
> > about 5" tall. The 5 MSR prints were together, and down at about the 2"
> > level, so it took awhile to get to them. The yellowing is distinct
> > enough that I had an immediate reaction when I saw the first one. None
> > of the matte prints had the yellowing. They were on a variety of papers,
> > both OBA and non-OBA versions (VFA, Condor BW, Soft Textured Art, EEM,
> > Photo Rag, Aurora Art, etc).
> >
> > Regards,
> > Clayton
>
> Hello Clayton,
>
> It must have been something that was in that paper from the beginning. I
> presume you did not rinse that paper for some reason. A sprayed varnish
> would show on one side only. Contamination, particles from the air
> around it, packaging etc most likely would have affected the other
> papers in the stack. Biological processes usually are not contained
> within the paper itself but transfer byproducts to the other papers in
> contact. If it is all around the edges light may not be the cause but
> more likely oxygen etc. Light would be less even around the edges with a
> stack in a bookshelf.
>
> Sizing of the paper or an anti-curl coating at the back with the same
> bad binder as used in the top coating. Bad batches of cotton fiber.
> Exposure to daylight might work if it is a sulfur or nitrogen effect. If
> it was oxygen or light it could worsen the effect. Nothing wasted to try
> that with one sheet, I guess.
>
> --
> Met vriendelijke groet, Ernst
>
> Dinkla Grafische Techniek
> Quad, pi�zografie, gicl�e
> www.pigment-print.com
>
>  
>


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