Re: [PPLetterpress] Building up roller tracks
- May I suggest that makeready is not merely placing paper under the base or
another sheet under the tympan. Traditional makeready, as outlined in Platen
Press Operations and General Printing, requires the "spotting" of makeready
tissue in the low areas of impression. Now, if the spots of insufficient inking
are moving, as may be inferred from your description, then it traces immediately
to the rollers, and then on from there. Even in the deep impression school of
printing, the edges of plates will "bear off" more than the center of the plate,
whether it be type or illustration, and this is true of platens and cylinders.
So, the solution is to build up the center portions of type areas, and then you
can back off a little on the overall impression, and that way the first letter
or two on each end of a line evens out in the impression and thus in the
printed/visual result as well.
I see many samples pass through our office from all over and that's the most
common problem. Ink rollers will likewise over ink the first part of a type form
or plate that the roller comes in contact with, especially if the roller is set
too low, and they also "bear off" to some extent--the outer areas of a form will
look great, but the roller may barely touch the inner area, and thus inking
problems. The harder the roller, the more the problem.
Hard rollers seem to have wide acceptance among letterpress people because they
cost a lot to have them recovered. We get Vandercook rollers in that measure in
the 60 to 80 Shore D durometer range, whereas new they are made to the 18-22
Shore D range. Offset rollers start at about 28 Shore D, and even that's too
hard for good letterpress. I realize that most letterpress people don't have a
durometer gauge in their desk drawer, but we do, and that is what I see on
almost every one of the several thousand rollers we have recovered. If the tape
routine doesn't work, the changing of trucks doesn't work, if someone's
wonderful base system doesn't work, look at the single most important link in
----- Original Message -----
From: "Carole Aldrich" <carolealdrich@...>
I kept using makeready sheets during these adjustments to keep
from using my "good" paper. If I raised the plate with a tiny piece of thin
would ink too much. If I took the paper away, too little. Ditto for adjustments
tape on the roller tracks. Adding a piece was too much, without it, too little.
like there was constant fiddling throughout the print run.
> hmmm...Stop! the vinegar will eat the polymer right up. That's what one is to use
> may be i'll dunk a piece of polymer into vinegar to see if it does anything...
> report back).
when cleaning platemaking equipment. It just melts the stuff.