U of S | Mailing List Archive | alt-photo-process-l | RE: Gum over Cyanotypes

RE: Gum over Cyanotypes

Hi Marek, my problem is the opposite. I expose Cyanotype bone dry, I
expose the gums very humid. Will try to solve this first...

Thanks & regards,

29 Nisan 2009, Çarşamba, 10:08 pm tarihinde, Marek Matusz yazmış:
> Loris,
> I do not print extra large prints, 13x17 is the largest. But as far as
> registration is concened I would consider my papers to be dimensionally
> stable after the initial soak. Registration on a light table also helps to
> register what is impoortant in the print.
> What I know for a fact and others have noted as well is that humidity at
> the time of printing makes a big difference. I have leaned never, ever to
> print my initial cyano layer on a rainy and cold day. I could never
> register these properly. Actually after I figured humidity is so
> imposrtant I could turn the heat up in the house and then some air
> contiioning to reduce humidity, or just wait for the sun to come out.
> I have not used a hair dryer in years. Always just hang them to dry. I
> work in batches of several prints and by the time I an done coating my
> first print is ready for exposure.
> The order of soak and size makes a difference IMO. My reasoning for sizing
> first and soaking later is as follows: gelatin shrinks more then paper
> when it dries, hence heavily coated papers will curl (like old B&W
> papers).
> If one coats the paper first and then soaks it to shrink later, the
> gelatin will shrink when drying and paper will shrink in soak, so they
> will both shrink "in synch". No specific measurements here, but I feel it
> reduces the curl.
> Marek
>> Date: Wed, 29 Apr 2009 11:33:09 +0300
>> From: mail@loris.medici.name
>> Subject: RE: Gum over Cyanotypes
>> To: alt-photo-process-l@usask.ca
>> Thanks Marek will try this.
>> It's amazing that you can print 10 layers w/o registration problems
>> using
>> the same negative. In my practice gum further shrinks paper when drying,
>> moreso where it's thicker than average (= dark shades of the print). I
>> can
>> see the relief on the back of the paper starting with the 3rd layer...
>> And
>> it's pretty stiff to the point of being able to curl 300gsm paper in
>> case
>> of low key images. Now I'm confused. Will try thoroughly shrink the
>> paper
>> as you/Don and others describe and see what happens...
>> Regards,
>> Loris.