Re: Optimal Roller Durometer
- Gerald, thank you -- I appreciate not only the data but a better
understanding of why you would want a roller a bit harder or softer.
It makes sense. Kathryn
In PPLetterpress@yahoogroups.com, "Gerald Lange" <bieler@w...> wrote:
> If I remember correctly the factory specified hardness for Vandercook
> rollers is 20. If you were just using photopolymer plates you might
> want to go a bit harder. I usually order rollers at 25 (for
> photopolymer). As the rollers age (exposure to UV light, solvents)
> they tend to get harder (though there is a dwell to the linearity). A
> durometer gauge will reveal the progression over time.
> Photopolymer plates, if set up correctly (precision base, etc), are a
> perfectly planar printing surface (sort of), and perform ink
> acceptance and transfer better if everything else is perfectly flat,
> cylinder packing, rollers. Softer rollers are better for irregular
> printing surfaces such as worn type or photomechanical engravings with
> poor base support.
> Gerald Lange
> The Bieler Press
> --- In PPLetterpress@yahoogroups.com, "kathryn_nyc" <kj.clark@f...>
> > Hello, I've searched through the postings and found a few postings
> > from a couple of years ago on roller durometer (Feb 2002). So I have
> > that information. What I did not see was any indication of the impact
> > on printing from either plates or metal type with a roller that was
> > A20 durometers vs. A25 vs. A35.
> > Any insight as to the impact on printing or why you prefer one spec
> > over the other would be appreciated. We are working with a Vandercook
> > Universal III and will be printing from type and plates. Thank you in
> > advance -- the postings I have read so far have been very helpful.
> > Kathryn Clark, Rhinebeck, New York