Re: Pictorico in a Vacuum Frame

Hi Silvina,

Drawdown time is the amount of time you wait after putting everything
into the vacuum frame and turning it on. Generally, I've heard 90
seconds is a reasonable amount of drawdown time to wait for everything
to settle down tight in the frame prior to exposure. Someone
recommended that to me as a cure for some problems I was having with
newton rings, but it actually made the problem worse with KM73 plates.

I've retrofitted my vacuum frame, removed the glass, and replaced it
with Kreene plastic. My current setup and procedure for processing
plates is documented here (and is still something of a draft):
http://www.lytescapes.com/procedures/polymer_photogravure.html

Dots that don't print don't sound like a problem. What do they look like?

Jon

Silvina GLATTAUER wrote:
> Hi,
>
> Can you explain what drawdown time is? Is it the vacum time? I seem to
> have similar problems even with Image setter negatives.
>
> Also, I've been using the Printight KM73 plates and have recently found
> that there are misterious dots on the plates after exposure, but they do
> not print.
> Any hints on this?
>
> Silvi
>
> */Silvi Glattauer/*
>
> */www.silvi.com.au/*
>
> */0417 377 962/*
>
>
> On 28/02/2006, at 5:24 AM, Jon Lybrook wrote:
>
>> Hi Jan,
>>
>> I didn't see my reply show up, so I'm sending it again!
>>
>> We're in Colorado, so the RH is pretty dry, though I haven't done a
>> reading in a while. My lab is in my basement, however, which has a
>> little added humidity to it.
>>
>> I think the anti-static stuff may be more of an issue because it picks
>> up too much baby powder, rather than the micro-coating on the
>> anti-static rag being a problem.
>>
>> Next time I'll try just using a hake brush to distribute and disburse
>> the baby powder and keep drawdown time to a minimum for the Pictorico
>> exposure and will let you know how it goes.
>>
>> Jon
>>
>> jpptprnt1@verizon.net <mailto:jpptprnt1@verizon.net> wrote:
>>
>>> Jon
>>> Are you still using the anti stat thing
>>> ??? how damp is your work space (RH)
>>> Jan
>>> From: Jon Lybrook <jon@terabear.com <mailto:jon@terabear.com>>
>>> Date: Sun Feb 26 20:51:29 CST 2006
>>> To: alt-photo-process-l@usask.ca <mailto:alt-photo-process-l@usask.ca>
>>> Subject: Re: Pictorico in a Vacuum Frame
>>> Hi Jan,
>>> Thanks for the idea, but a minute of warm air from a hairdryer over
>>> both the plate and the Pictorico didn't seem to change things.
>>> Should I have done something differently?
>>> Baby powder, in one thin coating, and minimal drawdown times, seems
>>> to be working the best, though it adds some steps to the process
>>> (powdering, powder reduction, and vacuum frame cleanup afterwards).
>>> Regards,
>>> Jon
>>> jpptprnt1@verizon.net <mailto:jpptprnt1@verizon.net> wrote:
>>>
>>>> Jon.
>>>>
>>>> Try this
>>>>
>>>> 1. Try drying the Pictrico with warm air
>>>>
>>>> 2. Hit the plate with warm air
>>>>
>>>> 3. Do not use the Anti Stat thing they have some sort of resido on
>>>> them like anti stat bags for computer part I think it may be transfering
>>>>
>>>> Jan Pietrzak
>>>>
>>>>
>>>> From: Jon Lybrook <jon@terabear.com <mailto:jon@terabear.com>>
>>>> Date: Fri Feb 24 18:31:50 CST 2006
>>>> To: alt-photo-process-l@usask.ca <mailto:alt-photo-process-l@usask.ca>
>>>> Subject: 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 Tue Feb 28 17:03:22 2006