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

Re: Gum and Photogravure, was: varnishes

I didn't say anything about oil paintings in general since the substrate
is usually sealed before painting onto... (But nevertheless oil painting
has its own problems in other areas - not that it doesn't own its own
advantages in others.) About gum, the first thing that comes into my mind
is the fact that there are whole bunch of *pretty old* watercolor
paintings in museums / collections and such. Since the binder in
watercolor paints consist of mostly gum arabic, I don't see any reason to
be suspicious about it.


16 Kasım 2008, Pazar, 1:19 am tarihinde, Jon Lybrook yazmış:
> I agree.  Thanks Loris.  And yes, the best oil-based etching inks are
> made from linseed.
> I believe you are right about carbon, from what little I know about it,
> but is there any evidence to support the idea that a gum print is more
> stable than an oil painting (or oil-based photogravure print)?
> Thanks,
> Jon
> Loris Medici wrote:
>> 15 Kasım 2008, Cumartesi, 9:30 pm tarihinde, Jon Lybrook yazmış:
>>> ... Oil based ink on cotton rag or alpha cellulose paper is essentially
>>> pH neutral anyway, isn't it? ...
>> Shouldn't be if it's the same oil (linseed oil) they use in oil
>> painting... But of course since it's a lot stiffer than regular oil
>> paints
>> it should have much less oil. Anyway, the oil (and acid) is still there.
>> So, I wouldn't consider a photogravure print as archival as say a carbon
>> or gum print made with non-fugitive pigments. But probably the
>> comparison
>> is moot - only a consideration for historians...
>> Regards,
>> Loris.