Re: Halftones and photopolymer
This seems fairly lucid. Thanks. Some other technical manipulations
such as dodging and burning appropriate areas would result in better
reproduction but I doubt most folks are all that skilled in these
matters. I don't know that the planar imagery is all that appropriate
for letterpress anyway but that doesn't stop folks from trying.
I'm currently looking at the restoration of an old copper plate
engraving for a fellow. Far more engaging and much more my cup of tea.
--- In PPLetterpress@yahoogroups.com, "John G. Henry" <JohnH@i...> wrote:
> When setting up halftone images in Photoshop, I generally do flatten
> the image a bit (reducing the contrast) as you tend to gain contrast
> through the halftone process. In whatever program you are using, you
> need to make certain that you have at least a good 10% dot in the
> highlight, and a 90% dot in the shadow. If you start to lose either
> end, the image starts to become very muddy and or spotty in appearance.
> I was always taught that dropouts (no dot at all) were OK
> in "specular" highlights. That is areas in which you would expect no
> density at all such as bright reflections. It seems to me that dropped
> dots become very obvious when dealing with line screens under 133
> lines/in., and dropouts should be avoided if possible.
> In my opinion, a 20% dot would be too heavy for something which has
> detail in the highlights you wish to keep, but experience with various
> papers and images is the best teacher. Most recently I have been
> printing halftone images for miniature books, where the images are
> small and detail is important. At 133-line screen, with coated paper,
> it is surprising what detail can be resolved. Even after considerable
> experience with the process, I am still frustrated on occasion with
> the results. More often than not, however, control of the process
> leads to better images.
> John G. Henry
> Cedar Creek Press