Re: Gum preparation

On reflection, I think the humidity proably has very little to do
with it; the only difference in an area of low RH, it seems to me, is
that you'd be able to coat again faster, as it would take a much
shorter amount of time than it does here for the paper to dry to the
right dryness. And by the same token, thinner papers take less time
to dry. It used to take 3 hours or so for the Arches traditiional
paper to dry; the Arches bright white I use now dries in more like 45
minutes, as it's a thinner crisper paper. It's just a matter of the
paper being the same level of dryness each time you coat, as Judy said.

Katharine

> Yves, look, I'm only here to tell you what works for me. This
> works for me, and yes, the high humidity where I live may have
> something to do with it, but not necessarily, as I'm not the only
> expert gum printer who works this way. If you print a lot of gum,
> you get a feel for when the paper is exactly dry enough to coat
> again. I do check the registration marks each time, before I coat,
> to make sure I've got it right; there's nothing particularly
> supernatural about it.
>
> Katharine
>
>
>
> On Apr 29, 2006, at 6:36 AM, Yves Gauvreau wrote:
>
>
>> Katharine,
>>
>> like you I know I have a good eye for some things. I could in my
>> prime align
>> a peg to within 1/8 of an inch between two other pegs separated by
>> a 100
>> feets. Good, maybe but what you do is out of this world, how much
>> would you
>> say one can be off on a 8" x 10" print before people start noticing
>> misalignment. Base on other ideas, it is said we can resolve 5
>> lines per
>> milimeter, Sandy King wrote the other day it could go as high as
>> 20 lines
>> per mm, that less then 1/1000 of an inch.
>>
>> Find me an industry anywhere in the world that as to build parts
>> or objects
>> within tolerance of 1/1000 or even only 1/250 (5 l/mm) of an inch
>> and there
>> quality control is done by eyeball...
>>
>> In your favor I'll add this, some time back you said the relative
>> humidity
>> is pretty high and constant where you live, if it's near a 100%
>> you probably
>> don't have shrinking problem to begin with. This would explain
>> away your
>> apparent supernatural habilities.
>>
>> Regards
>> Yves
>>
>>
>>
>>
>> ----- Original Message -----
>> From: "Katharine Thayer" <kthayer@pacifier.com>
>> To: <alt-photo-process-l@usask.ca>
>> Sent: Friday, April 28, 2006 6:52 PM
>> Subject: Re: Gum preparation
>>
>>
>>
>>
>>> I've probably said here before that I've never preshrunk paper and
>>> that when I was in full production with tricolors, I could tell just
>>> by the feel of the paper when it would be the right size to recoat.
>>> kt
>>>
>>>
>>> On Apr 28, 2006, at 3:43 PM, Judy Seigel wrote:
>>>
>>>
>>>
>>>>
>>>> On Fri, 28 Apr 2006, Yves Gauvreau wrote:
>>>>
>>>>
>>>>
>>>>
>>>>> I notice the paper I used up to now was changing in size quite a
>>>>> bit. I
>>>>> simply couldn't do more then a single exposure of a 4x5 step
>>>>> tablet on it,
>>>>> this mean a larger negative would be a lot worst.
>>>>>
>>>>>
>>>>>
>>>>
>>>> Yves, any paper in any dimension no matter how well soaked or
>>>> boiled or treated with incantations, will almost certainly change
>>>> size if it's not at the same level of dryness (or humidity) when
>>>> you coat. If the humidity is constant where you live, timing the
>>>> interval between coats may suffice. Or set up some standard
>>>> procedure, which should also help....
>>>>
>>>> Some years ago I tested 4 different papers with & without presoak
>>>> and measured at various stages-- after coating, after drying, after
>>>> developing, etc. The paper could expand or contract throughout the
>>>> process. We only get a "set" dimension by luck, or paying attention
>>>> -- or holding the paper rigid, which is another production.
>>>>
>>>> J.
>>>>
>>>>
>>>>
>>
>>
>>
>
>
Received on Sat Apr 29 08:53:32 2006