U of S | Mailing List Archive | alt-photo-process-l | Re: Newton Squashed Under Pressure (photogravures)

Re: Newton Squashed Under Pressure (photogravures)

SusanV wrote:
Hi all,

After a long time of troubleshooting this problem I've had of tiny
little irregularities of tone, not measles, but speckles... This is my
current thinking.  They ARE caused by Newton's rings between both the
imagesetter film and Pictorico OHP and the glass of my vacuum table.
It's been suggested it was caused by not using enough pressure when
printing (intaglio), but what I have found is that additional pressure
does eliminates the speckles ***which have been caused by newton's

Furthermore, the reason my speckles are tiny and numerous, has to do
with vacuum pressure of 22".  The more pressure I use, the smaller the
rings become, but they also become more numerous.
Tiny speckles? Newton rings generally look like tiny gray-black droplets or spots of varying sizes on the print from my experience. Not speckles. Could you please post an example or two and indicate the problem areas?
My goal now is to settle on one of the several solutions to Newton's
rings (clear spray on the back of the inkjet positive, frosted mylar,
Kreene plastic, etc ), so that I can use less pressure when printing,
reducing wear and tear on my press over time (not to mention my biceps
are beginning to develop to Popeye proportions :^O )
I'm confused. Why would solving newton ring problems allow you to use less pressure on the press? Polymer photogravure always requires alot of pressure to get a crisp impression. No way around that.

The standard, coarser aquatint screen results in speckles in the final print, which is why I don't use it...is that what you're seeing?