U of S | Mailing List Archive | alt-photo-process-l | Re: solarplate wedgies

Re: solarplate wedgies

Hi Jon,

yeah that does help.  I've been focused on the problem being with the
exposure or newton rings or or or... but haven't thought much about
the press.  My press is new, so it works properly and isn't warped,
and it has a 10" diameter roller.  The blankets I have are new, too.
That could be good or bad, who knows.  Maybe old, sizing and
ink-encrusted blankets work better ;o)   I'll experiment with the
press and blankets tomorrow.

One other thing I was considering is whether it's being caused by the
combination of my printer and the weldon aquatint screen.  Maybe some
kind of moire pattern thing happening.

The good news is that now I can print the most beautiful Precision
Digital Negatives you've ever seen.  Hallelujah, I have seen the
light!  And the dark.  And the curve in between :o)))


On 4/4/07, Jon Lybrook <jon@terabear.com> wrote:
Those look like marks related to not using enough pressure in the
press.  I get them sometimes too, and when I do, I either have to crank
down the pressure on the press, or run it through the press twice (or
both) -- once through and then back.  Similar patterns sometimes show up
due to the blankets if they're too coarse.  I usually put a sheet or two
of newsprint on top of the paper before putting the blankets down and
running it through the press to ensure patterns from the blanket don't
get into the print.

How big is the drum on the press you're using?  I used to use an abused
little Takash press with a 5" drum.  Turns out due to the drum size
and/or wear and tear on it, it simply inadequate for printing poly
gravure.  I switched to a press with a 10" drum and rarely have this
problem now, except occasionally when I'm printing full A2 sized plates.

Hope that helps!


SusanV wrote:
> Hey Jon,
> Go look at my blog.  All the way down at the bottom of the page there
> are images of a step wedge showing the speckles.  They aren't large
> areas of tonal difference... they're small "squiggles" of lighter tone
> that show up mostly in the mid to lights.  I think the darker tones
> just mask them though, because those areas are holding more ink, and
> it gets smeared around on the tops of the light spots and doesn't get
> wiped off.
> susan
> gravure blog at www.susanvossgravures.blogspot.com
> website www.dalyvoss.com
> On 4/4/07, Jon Lybrook <jon@terabear.com> wrote:
>> Hi Susan,
>> Can you post a scan of the irregularities?
>> Thanks,
>> Jon
>> SusanV wrote:
>> > Well I got mixed results.  It (acetate as described below), eliminated
>> > any visable newton's rings, but darnit I still have some very
>> > small-scale irregularities of tone that I just don't understand.  It's
>> > much better than it was however, so I'm not toooo discouraged.
>> >
>> > Susan
>> >

gravure blog at www.susanvossgravures.blogspot.com
website www.dalyvoss.com