RE: PVA for gum printing (Re: Artistico Unsized?)
Yes, it has been used a lot especially in industry, so if I ever get to do
testing/research, it won't be the technical in academic sense (like the
study of how this particular polymer polymerize or the study of chemistry of
it) but rather the application of it in printmaking.
> -----Original Message-----
> From: Katharine Thayer [mailto:email@example.com]
> Sent: Saturday, August 25, 2007 5:19 PM
> To: firstname.lastname@example.org
> Subject: PVA for gum printing (Re: Artistico Unsized?)
> For whatever it's worth, PVA (polyvinyl alcohol) has long
> been used as a substitute for gum; since dichromated PVA
> apparently behaves chemically like dichromated gum arabic
> (the crosslinking mechanism is assumed to be the same) the
> research on dichromated PVA is what we use to try to
> understand the chemistry of dichromated gum, since there's
> virtually no research on the mechanisms of dichromated gum per se.
> There are many variations of PVA and not a consensus on what PVA
> works best as a substitute for gum in a dichromated colloid
> it comes in an endless variety of types depending on
> molecular weight (length of chain) and degree of hydrolysis
> among other characteristics.
> David Hatton, several years ago, provided us a wonderful link
> to a site that explained how the different PVAs behave,
> depending on their different characteristics. I went looking
> in the archives for the link and actually found it (my
> success at finding things in the
> archives hasn't always been so good) but when I clicked on
> the link,
> it took me to a page that was all in perhaps Korean, so I
> guess that link doesn't work any more.
> Mike Ware, several years ago, shared with me some research a
> student of his did to determine what PVA works best for gum
> printing; he gave
> me permission to share that information, with proper citation.
> Here's an excerpt of the post where I shared that with the
> list, gleaned from the list archives:
> "He said that they settled on was a "polyvinyl alcohol-acetate; i.e.
> only partially hydrolysed co-polymer, which is much more
> easily dissolved in water than the pure alcohol. We found an
> 88% hydrolysed PVA, with an RMM around 25 kD in 20% w/v
> solution, to offer the best all-around results-- comparable
> to a 14 Baume Gum."
> "If you make any public use of this information in the
> future, please acknowledge the original experimenter, by citing:
> Stephen Beckett, M. Phil. Thesis, University of Derby (UK),
> November 1993. (A private communication from Mike Ware)."
> Just out of curiosity I tried printing with PVA some time
> ago, in the
> form of "gloy." Keith Gerling was kind enough to share a thimbleful
> of his supply of gloy with me, so I was only able to make a
> couple of
> small test prints, but in that limited experience, I couldn't tell
> any great difference from gum. It looked like gum, felt like gum,
> coated like gum, printed like gum (same exposure as my usual, same
> number of steps (8) compared side by side with my gum of choice at
> the time, using the same pigment mix, etc.
> On Aug 25, 2007, at 6:37 AM, Dave Soemarko wrote:
> > First time I heard of it. I just did some search, and it looks
> > interesting.
> > Thanks for the info!
> > Dave
> > From: henk thijs [mailto:email@example.com]
> > Sent: Saturday, August 25, 2007 9:10 AM
> > To: firstname.lastname@example.org
> > Subject: Re: Artistico Unsized?
> > On 25 aug 2007, at 14:39, Dave Soemarko wrote:
> >> << What is of no interest for the paper, but just for info:
> >> he uses no gumarabic -he hates formaldehyde or similar- but uses
> >> Mowiol 88 in stead .... >>
> >> Henk,
> >> What is Mowiol 88?
> > Hi Dave,
> > On the box is written:
> > Polyvinyl alcohol 8-88 ; small clear crystals , if you want to use
> > it and needs some info about percentages etc. just ask.
> > I ordered it from Kremer Pigmente (on the box the name FLUKA is
> > obviously the manufacturer).
> > Last time i contacted them, they told me that the 8-88 is not
> > produced anymore, but the 4-44 would be the same , apart from the
> > concentration (!)
> > cheers,
> > Henk
> > ------------------------------------
> > www.thijs-foto.com
> > ------------------------------------