U of S | Mailing List Archive | alt-photo-process-l | Re: Gum and Photogravure, was: varnishes

Re: Gum and Photogravure, was: varnishes



Hi Loris,

With intaglio printmaking no preparation is made other than soaking the paper in water and blotting it somewhat dry.  This removes some sizing and helps transfer the ink from the plate to the paper.  The quality and thickness of the printmaking paper and that of the etching ink used is what we rely on to keep it from soaking through.  However even some quality tissue papers will allow the ink to pass through to the other side somewhat, which is fine in most cases.

If you print using oil *paint* rather than oil-based ink on the plate, certain colors do tend to leech through however, bleeding oils, and discoloring the paper and print in an undesirable way.  This is why printmakers, especially those doing monotypes, generally stay away from oil paints and stick to oil-based ink only.  Oil paint seeps into and through paper fibers where properly mixed etching ink made for intaglio does not.

Katherine - thanks for your response about gum and carbon having similar stability.

Just out of curiosity, does anyone else believe that photogravure prints are less chemically stable than either gum or carbon because of the presence of linseed oil in the ink? 

Wouldn't the information in this thread so far also imply that watercolor paintings then last longer than oil paintings because of the assertion that gum arabic used in watercolors is less acidic than linseed oil?  This seems contrary to my vague sense about the longevity of watercolors vs. oil paintings.  I believe I've seen alot more old oil paintings in museums than watercolors, for example.  I'm neither a chemist, nor an art historian, nor a conservationist, but I'm wondering what people on the list who may be, either amateur or professional, know about this.

Many thanks,
Jon

Loris Medici wrote:
51851.85.99.254.37.1226796457.squirrel@loris.medici.name" type="cite">
Hello Jon,

What you wrote below, I don't understand (probably because of my ignorance
about photogravure). What measure is taken in photogravure, to prevent oil
sinking to the paper (acid free or not)? I remember someone mentioning the
darkening of the backside of paper in the darkest parts (= most ink) of
the photogravure image on the front -> isn't that the same phenomenon one
experiences when oil painting on unsealed paper?

Regards,
Loris.


16 Kasım 2008, Pazar, 2:34 am tarihinde, Jon Lybrook yazmış:
  
...I'm prepared to say a properly made oil-based photogravure print has
similar stability to a properly prepared oil painting...
    



  

-- 
Jon Lybrook
Intaglio Editions
http://intaglioeditions.com
303-818-5187