46Re: [PPLetterpress] contact frames
- Aug 24, 2001Thanks to all who have offered hints on washing out by hand. I seem to
recall that thinner plate material works better with hand-washing for some
reason. I always assumed it allowed the washing out to be quicker, with less
danger of washing away fine detail.
To hold the plate in place while brushing over it, my old pal Chip Schilling
in Minneapolis recommends putting down magnetic material in the bottom of a
photo tray, using adhesive that is not soluble in water, of course. I tried
this once with that thin magnetic stuff that you can get at Office Depot,
etc., for putting business cards onto. I was never able to get it to stick
to the tray, and the magnet on that stuff is very weak, so the plate would
not stick to it. It was frustrating! But it should work, in theory!
> From: "Joel Benson" <joel.benson@...>
> Reply-To: PPLetterpress@yahoogroups.com
> Date: Fri, 24 Aug 2001 09:56:00 -0700
> To: <PPLetterpress@yahoogroups.com>
> Subject: RE: [PPLetterpress] contact frames
> "Any hints on increasing success with hand washout?
> Katie Harper
> Cincinnati, OH"
> I've only hand-washed a few plates, when the motor in the washout
> machine I was using was broken. I just laid the plate face down on the
> brushes and rubbed, and it worked, but I remember it did weaken the
> small stuff (periods) and I had to re-do at least one of them.
> The thing I noticed is that when you expose your image or type or
> whatever, the polymer is not hardened all the way down to the backing
> material. It is only in the post-exposure that the shoulders and the
> under layers of the type/image are hardened. Consequently, during the
> washout, the shoulders of the type are weak, and easily washed away.
> I think the hardened face of the type protects the shoulders from the
> brush when the bristles are oriented close to 90 degrees to the face of
> the plate and only lightly and evenly touching. This precise
> brush-plate contact is harder to maintain by hand, so it is easier to
> undercut your printing surface, allowing things to wash away or get
> substantially weakened.
> The only hint I can offer is light, careful brushing. However, I can
> think of two possible experiments; perhaps someone has already tried
> these and can comment on their results. First, does washing with cold
> water increase resistance to the bristles, allowing the shoulders to
> hold up better? Second, does the thinner plate material hold up better,
> because the initial exposure may harden closer to the backing material?
> The stuff I use is .028 or something, but I know it comes thinner, like
> ..020 or some such. Maybe that makes a difference.
> Now my brain is going to be stuck all day on trying to think of a
> homemade jig for holding the plate flat and light against the bristles!
> If I think of something good, I'll post plans!
> Joel Benson
> Dependable Letterpress
> San Francisco
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