Judy Seigel (jseigel@panix.com)
Mon, 22 Nov 1999 22:22:25 -0500 (EST)
Joe, I think it depends on your printing style. I did extensive tests &
found the plate burner (mercury vapor thingum) bulb was indeed contrastier
& gave more density, & assumed it was therefore best, but when the blasted
thing broke down for the 3rd time & I switched to the BL fluorescents,
damned (excuse me,"darned") if the prints didn't print better & easier.
Which is to say this may be a pudding has to be proved in the printing,
not the test strip.
I also tried Phil Davis's daylight (I think it was) fluorescents, but they
were so very slow and so very contrasty seemed useless for gum. But Sam &
Sandy found them better for carbon.
Judy
On Mon, 22 Nov 1999 Smieglitz@aol.com wrote:
> Hello all,
>
> A recent conversation with another gum printer suggested that the fluorescent
> (BLB and similar) type tubes generally recommended in texts may not be ideal
> for gum printing. A vacuum plateburner was suggested to get better results
> (i.e., greater density and contrast range with a single coat, other things
> being equal). But, alas, I don't have one, and probably couldn't find room
> for it (or a tanning bed,) even if it was affordable.
>
> I've read through several years posts in the archive hoping to find an
> inexpensive alternative, but so far the posts have only served to bring up
> more questions. Foremost among them are:
>
> 1) does anyone know the sensitivity peak of potassium dichromate? (Mike Ware
> posted it as 365nm, but later posts appeared to suggest otherwise e.g., 420nm
> or 440nm.)
>
> 2) is there an inexpensive (< $100) and relatively *"point source"* UV-rich
> lamp (mercury-vapor, zirconium arc, quartz??? etc.) that someone has
> *actually had experience with* and could recommend for gum printing?
>
> 3) can anyone point to an online source of spectral emission curves for
> UV-rich lamps that may be readily available?
>
> It appeared as if Sandy King, Phil Davis and some others were investing the
> differences in UV output and peak sensitivities for awhile. Any definitive
> results or recommendations specifically for gum?
>
> Sorry to bring the UV thing up on the list again, but I kept getting
> sidetracked in the archive threads and couldn't find the answers.
>
> Thanks,
>
> Joe
>
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