Re: Gum over Cyanotypes
Yes, probably so... But that's impossible; for consistency I let the gum
layer in peace for several minutes (7-8 mins. average), then dry it with a
hairdryer until it doesn't shine like wet and it's dry to touch (not tacky
anymore), then I humidify both front and back using a sonic humidifier
(you should see me doing it; it's a ritual - totally consistent movements
and timing, almost OC behavior - hehehe). Humidity is what I need in paper
so that the gum exposures aren't too long. (+ I'm not sure, but, maybe dry
gum layer is more contrasty too? - Don't want that!)
If I can't affix the paper to a dimensionally stable support then I have
to learn to expose the cyanotype layer when the paper is equally humid (=
relaxed) as when printing gum - that seems to be the most feasible /
doable procedure. Don't you think?
28 Nisan 2009, Salı, 7:31 pm tarihinde, firstname.lastname@example.org yazmış:
> Hi Loris,
> Maybe it's not only shrinkage but also MOVEMENT in the paper? I
> suppose you should be drying the gum layer to the same degree as the
> first cyano coat.
> On Apr 28 2009, Loris Medici wrote:
> Hi David,
> The 300gsm (140lb?) paper had stayed at least 45-50 minutes in room temp.
> water (HCl pre-soak to get rid of the CaCO3 buffer + 5 water bath rinses
> to get rid of remaining HCl and CaCl2) and dried before making the
> cyanotype, doesn't that count for shrinkage? Does the water has to be
> considerably warmer than room temp.?
> Thinking again, my practice of cyanotype is to completely/thoroughly
> dry the paper with a hair dryer before exposure (to be safe from humidity
> fluctuations / which have a very pronounced effect on cyanotype), maybe
> that's the problem...
> 28 Nisan 2009, Salý, 11:17 am tarihinde,
> email@example.com yazmýþ:
> > Hi Loris,
> > Give the paper a good long soak in warm water before you print any
> > at all. That's what I do and shrinkage is minimal on the print
> > I produce
> > Regards
> > David
> > On Apr 28 2009, Loris Medici wrote:
> > I did few gum over cyanotypes recently and I happen to like them much.
> > See
> > the most recent one below here: http://dwarfurl.com/008fa
> > The print is on HCl acidified (2 minutes in 2.5%) Fabriano Artistico
> > One -1/3 stop exposed cyanotype layer + 3 gum layers. (1. PR206 5% AD
> > +1/3
> > stop exposure, 2. PV19 Rose + PBk9 5% AD normal exposure, 3. PBk9 2% AD
> > +1/3 stop exposure.)
> > I print the Cyanotype on unsized paper, then size with 3% gelatin.
> > sizing, the paper change dimensions and you can't register the
> > negative
> > perfectly on the first gum pass - 2mm larger in both horizontal and
> > vertical orientations (print size 10x6.6"), the registration gets
> > perfect
> > only in the second or third gum pass. (See the resulting blur at the
> > right
> > edge in the middle.)
> > My question is: How do you manage to get perfect registration for gum
> > over
> > layers?
> > Any tips and tricks would be highly appreciated.
> > Regards,
> > Loris.
> > P.S. I have read Lukas Werth's method somewhere else: Affix the
> > on
> > dimensionally stable support - such as an aluminum sheet - with
> > print, varnish the print (acrylic binder + mineral spirit) to
> > "protect"
> > the gum layer and then put the print in warm water (this is where you
> > need
> > "protection"!) to melt the gelatin and release the print from
> > the support.
> > I would like to hear about any suitable varnish that can be used for
> > purpose too...