Re: Pictorico in a Vacuum Frame

Hi All,

I think baby powder, along with some modifications to my procedure, worked.

There's definitely an issue with the way Pictorico makes contact with
mylar-protected poly plates, such as the KM73. Both are somewhat tacky
(once the mylar is removed from the plate). The longer the drawdown, the
more newton rings appear around the peripheral of the plate, encroaching
toward the center, like leprosy. This does not occur with imagesetter
film, only the Pictorico.

The solution for me seems to be to only apply baby powder to the plate
after exposing the aquatint screen. I follow Jan P's advice from 2
years ago on how to apply the baby powder: Dust the plate, tap it off
one end, then the other, dust off with a hake brush using crosshatch
strokes. I then do a final wipe with an anti-static cloth to remove
even more, then make sure there's no pattern in the powder remaining on
the plate, as much as possible, before exposing the transparency. I
also keep drawdown time to a minimum in both cases - just enough to let
all the air evacuate the vacuum frame and ensure good contact has been
established. I may be more liberal with the drawdown time in the
future, but for now, less is definitely more.

Cheers,
Jon

Jon Lybrook wrote:
>
>
> Jeremy Moore wrote:
>
>> Jon, how long are you waiting and letting the ink cure before
>> printing? The ink may still be wet in patches and the vacuum frame is
>> pulling the ink off.
>>
>
> Hi Jeremy,
>
> Thanks for responding. The ink had been dry for well over 24 hours.
> Also, the pattern of patches was random from plate to plate and there
> was no sign of damage to the transparency.
>
> Jon
>
>
>
Received on Fri Feb 24 18:32:27 2006