Useful results from gum tests

Katherine, May I say, but not as a gum printer, that I found your three examples extremely impressive especially when I printed them on glossy photo quality paper. The last one looks acceptably sharp which you printed on paper, ''on a somewhat less- pigmented gum emulsion''. I join with
----- Original Message -----
From: "Katharine Thayer" <kthayer@pacifier.com>
To: "alt photo" <alt-photo-process-l@sask.usask.ca>
Sent: Monday, April 10, 2006 7:33 PM
Subject: Gum hardening: top down?

> Okay, I've coated a very thick, very heavily-pigmented gum emulsion on
> mylar and printed it from the front and from the back. A couple of
> comments before I give you the URL:
>
> (1) though the emulsion was very heavily pigmented, two things resulted
> in not a very deep DMax: (a) the fact that I used ivory black, a
> transparent pigment (if I were to do it again, I'd use lamp black) and
> (b) the fact that it's printed on a transparent material and was scanned
> as a transparency, with the light shining through it. But the thing to
> note is, be that as it may, the DMax is about the same in both prints.
>
> (2) there's a light brown pigment stain (ivory black is a brownish black)
> in both prints that is probably a function of the heavy pigmentation. It
> hardly shows in the prints themselves, but for some reason was
> accentuated in the scanning.
>
> (3) I don't honestly know what to make of the results. If you look just
> at the prints on mylar, you'd have to conclude that back- printing is much
> superior to front-printing, at least for a thick coat on mylar. But if
> you compare the back-printed print on mylar to the regular front-printed
> gum print (using a less heavily-pigmented emulsion) on paper (at the
> bottom of the page), it's hard to claim that the back-printed print is
> superior. But since they are on different materials, it's apples and
> oranges.
>
> So I guess if I were forced to draw a conclusion from this rather
> inconclusive test, I'd say that if you are going to print on mylar using
> a very thick and heavily pigmented emulsion, then you'll probably do
> better printing from the back. But if you're printing on paper, you can
> get fine results printing from the front with a less pigmented emulsion.
>
> http://www.pacifier.com/~kthayer/html/topdown.html
>
> Katharine
Received on Tue Apr 11 09:37:36 2006