From: Jack Brubaker (jack@jackbrubaker.com)
Date: 04/15/03-11:02:01 AM Z
From: Jack Brubaker <jack@jackbrubaker.com>
Reply-To: alt-photo-process-l@skyway.usask.ca
Date: Mon, 14 Apr 2003 16:00:30 -0500
To: alt-photo-process-l@skyway.usask.ca
Subject: Re: Acrylic size (was Mixing a light pigment for gum)
I realized that I had typoed the name of the material I used below (prior
transmission) Disregard the "nbsp;" in the Golden Matte Medium name. I have
no idea where that came from...
Jack
I am so glad to hear some comments on acrylic sizing. It's all I have used
to size for gum. My standard has been to use Liquitex Matte Varnish 1:1 with
water. I have had a large supply of the old matte varnish that I have used
for years. I just realized it is no longer made. Don't know when they
changed to the current product line but the Liquitex handouts at my local
shop no longer include the Matte Varni sh. I spent this weekend testing six
Liquitex and Golden products that seemed promising. I diluted each 1:1 with
water and brushed on samples of two papers. One set was on Lana the other on
Fabriano 100-100 cotton. Neither is a paper that is great for gum. Even with
sizing Lana seldom prints clear whites. None of the sizes I used printed
good whites on Lana. Both papers printed best with Golden Polymer Varnish
with UVLS (Satin). The UVLS is a UV blocker that is to prevent fading. It's
of no importance in gu m printing since it will be under the image, but that
's the way it is sold. The other products I tried include:
Golden Poly Varnish with uvls (gloss)
" " " " (Matte)
" nbsp; Matte Medium
Liquitex Matte Medium
" Gloss Medium and Varnish (that's one product not a mix I made)
The Golden varnishs seem to be consistantly better than the other options I
tried.
I also tested my old size as a standard to compare the above. However the
last dregs in the bottle of diluted acrylic had gone bad (turned yellow) and
didn't work as a size. I have had diluted acr ylic grow mold before but
never turn yellow. I usually mix what I'm using that day as I go but I used
to add a few drops of ammonia to the dilute mix and that seemed to keep it
from molding.
This is only a beginning point for testing sizes. The interesting thing I
saw in this limited trial was that both papers had a better light tone with
the Satin Golden varnish. I was printing a 21 step scale on each size with
the same black gum mix. On the other sizes the lightest tones to print broke
up in a very visible texture of light pigment-no pigment. The Satin held a
thin light tone with little tendency to break up. I didn't get as clean a
white as I am used to getting with my old size on any of these trials. More
work needed but I think I learned where to put my efforts.
What acrylic size are others using? I have a real interest in being able to
size without using the offensive chemicals associated with using gelatine
size. Perhaps I should be looking at other sizes beyond acrylic...
Dave, two coats! I never tried that. I suppose each retains its open texture
needed to hold the gum even though it is a thicker layer with two coats. Or,
do you use a more dilute solution with two coats?
I have felt so smug having a size that worked well for me for 35 years. It's
pay back time.
PS I thought that everyone was using gelatine and I was the odd crank. Glad
to hear I'm not alone.
Jack
I almost never use 1 coat, always 2 coats or more. Maybe it i s just
psychological or the effect of engineering training which says that
averaging even outs random noise.
But considering your test, the first test was 1+1, the second 1+9. The jump
is high. I would, for example, test 1+1, 1+3, 1+6, 1+9 at the same time.
Dave S
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