U of S | Mailing List Archive | alt-photo-process-l | Re: Unknown areas in Gum printing?, etc.

Re: Unknown areas in Gum printing?, etc.

Well, each to his own experience, Katharine, to be sure, but
the gelatin and the layer were firmly cemented together with
no image showing, much like Carmen's experience she had with
a fresh layer of size and magenta.  AND I did an exact side
by side on a hardened gelatin substrate which showed and
developed into an image. One could explain it to be acute
staining but it was far different than any acute staining
I've experienced where at least an image shows.  I think my
explanation is perfectly....undeserving of derision.

And, speaking of derision, gee--I might prefer a few LOLs
and LMAOs better than all the myriad other accusations I
have taken in over the years...and Jacek, NO ONE was
deriding you at all.

The bottom line--sizing without hardening is very
problematic even for veteran gummists.

----- Original Message Follows -----
From: Katharine Thayer <kthayer@pacifier.com>
To: alt-photo-process-l@usask.ca
Subject: Re: Unknown areas in Gum printing?, etc.
Date: Tue, 01 May 2007 09:54:19 -0700

>I hate to disturb all of you folks falling on the floor
>laughing and   whatever other kinds of hilarity the rest of
>the acronyms stand for,    but you're all laughing at the
>wrong thing, seems to me.
>I have to wonder if any of you who are laughing so hard
>actually   looked at Jacek's step tablets.  At any rate, as
>has often been   pointed out in the past,  there are people
>other than Terry King who   have used unhardened gelatin
>for a size and found it worked quite   well; I used
>unhardened gelatin as a size early in my gum printing  
>career,  with no problems .  But I've come to believe that
>in cases   where unhardened gelatin works well as a size,
>the same paper will   probably work well unsized, at least
>that's been my experience.  So   in Jacek's predicament, of
>not being able to get hardeners,  I'd   suggest trying the
>Fabriano paper that worked well with unhardened   gelatin,
>without bothering to size.  (I can't remember if he tried  
>that with the Fabriano paper, or only with the Arches).
>At any rate,  if you want something to fall off your chair
>laughing   over, the idea that if you print gum on
>unhardened gelatin, the   dichromate will harden the entire
>layer of gelatin, is the laughable   idea here, not the
>idea that unhardened gelatin can serve as a   reasonable
>size.  If you print gum on unhardened gelatin, of course  
>the dichromate doesn't harden the gelatin overall, any more
>than the   dichromate hardens the gum coating overall.  The
>hardening occurs   differentially as a function of exposure
>, in both the gum coating and   the underlying gelatin
>layer. This is the fundamental underlying   principle of
>gum printing, and carbon printing too; neither of them  
>could occur without this principle holding true. So this
>statement   that the dichromate would harden the whole
>layer of gelatin isn't   consistent with an accurate
>understanding of how dichromated colloids   work.
>I've had on my website for several years a demonstration of
>what   actually happens when gum is printed on unhardened
>gelatin:  as could   be predicted from a knowledge of the
>process, the dichromate in the   gum emulsion hardens the
>underlying gelatin exactly where exposure   occurs.  Where
>exposure doesn't occur, the unhardened gelatin stays  
>unhardened and can be washed off with hot water, if a
>person is   concerned about the archival properties of
>unhardened gelatin,   without disturbing the hardened gum
>or the hardened gelatin under the   hardened gum.   It may
>not be the most efficient  way to size, but   there's
>nothing particularly wrong or stupid about it either. 
>Here's   the page:
>I personally would prefer a more reasoned and professional
>discussion   of issues; this hooting and jeering and LMAO
>and LOLOL and other   juvenile expressions of disrespect to
>colleagues is very annoying on   a professional forum and
>doesn't speak well of our community,    besides it shuts
>down a reasonable discussion of issues.  Jacek, when   he
>couldn't find hardeners available, tried printing without a
>  hardener, and the thing is, it's not that unreasonable an
>idea,  as I   and others have demonstrated.  It certainly
>didn't deserve all this   ridicule.
>Katharine Thayer
>On May 1, 2007, at 8:16 AM, john@johnbrewerphotography.com
>> www.johnbrewerphotography.com
>> ----- Original Message ----- From: "Christina Z.
>> Anderson"   <zphoto@montana.net>
>> To: <alt-photo-process-l@usask.ca>
>> Sent: Tuesday, May 01, 2007 3:55 PM
>> Subject: Re: Unknown areas in Gum printing?, etc.
>>> LOLOL yeah, you ain't a kiddin', don't you remember when
>>> I took up   Terry King's suggestion to use unhardened
>>> gelatin for a size and   got wonderful black squares of
>>> no image because, OF COURSE, the am   di in the
>>> gum/pigment mix LOVED the unhardened gelatin and  
>hardened that into a nice complete layer, too.  So much for
>>> 250   bloom gelatin and all that.
>>> Chris
>>> ----- Original Message ----- From: "Loris Medici"  
>>> <mail@loris.medici.name>
>>> To: <alt-photo-process-l@usask.ca>
>>> Sent: Tuesday, May 01, 2007 8:48 AM
>>> Subject: RE: Unknown areas in Gum printing?, etc.
>>>> Oops! Sorry for mis-quoting, it was Marek then...
>>>> Anyway, that could be better than trying to print on
>>>> unhardened   sizing
>>>> (+ w/o struggling to buy a locally restricted chemical)
>>>> - at least, that's how I take it ;)
>>>> Regards,
>>>> Loris.
>>>> -----Original Message-----
>>>> From: Christina Z. Anderson [mailto:zphoto@montana.net]
>>>> Sent: Tuesday, May 01, 2007 5:37 PM
>>>> To: Alt, List
>>>> Subject: Re: Unknown areas in Gum printing?, etc.
>>>> Just for the record, Loris, wasn't it Marek or Terry
>>>> King (not   me) who
>>>> recommended a hardened layer of di/gum?
>>>> If the highlights are protected, there will be slight
>>>> tone in   them with
>>>> the di/gum layer, which adds an overall dullness to the
>>>> But what do I know, I'm one of those glutaraldehyde
>>>> addicts, you   know...
>>>> Chris
>>> -- 
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