Re: Tiny Bubbles In The ... Gum

From: Judy Seigel ^lt;jseigel@panix.com>
Date: 08/30/05-10:31:10 PM Z
Message-id: <Pine.NEB.4.63.0508310013590.8906@panix2.panix.com>

On Mon, 29 Aug 2005, Tom Ferguson wrote:
> Bubbles: If you are really getting three dimensional bubbles (as opposed to
> uncoated spots or flakes of coating washing off in development) try adding
> some cheap vodka to your mix. Really, I'm not kidding! I use 1:10 (1ml vodka
> for every 10ml of mix). It reduces bubbles and makes the whole coating more
> even and simple to apply. Some gum printers will say you need to use
> Everclear, a very high proof alcohol that is illegal in many states
> (including mine).

I think it's the alcohol, whether as vodka or Everclear, or IME just plain
isopropyl rubbing alcohol that somehow persuades the emulsion to grip or
sink into an area that's otherwise too slippery to absorb it. That may be
due to over-sizing, but I used it (with some success) to add a coat to
an area already clotted with too many coats of hardened gum.

However, for a sizing or other undercoat with just spots of resistance
(the "fish eyes"?), I've found a drop or two of Tween-20 (kept in a
dropper bottle & added to the problem area in work) is best. It smooths
the coating miraculously as the trouble appears. The alcohol has to be
added at the beginning, which means forseeing the future to some extent. I
think the Tween-20 can be added during work because a drop or two is such
a relatively small volume. The alcohol took more.

Also I think it was Tom (whose coating method is my finding also) who
mentioned that you can always add subsequent coats of gum. Except if you
haven't preshrunk the paper, you probably run into re-register problems.
IME, preshrinking does require an added gelatine size, tho not everyone
finds that.

Judy

> Hope that helps.
>
> --------------
> Tom Ferguson
> http://www.ferguson-photo-design.com
>
>
Received on Wed Aug 31 10:41:20 2005

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