Richard Hamilton collotype print

Janice Stagnitto Ellis <jellis [at] quartoconservation__com> writes

>We have recently been asked to treat a 1971 collotype print by
>British Pop artist Richard Hamilton entitled "Black Christmas". ...

As part of my misspent youth, I served as a master printer working
in fine art serigraphy. I have some general comments that might be
useful to Janice Ellis' research.

My understanding is that the collotype system uses a hygrophobic ink
transferred (under pressure) from a water-based resist to the paper
surface. This might slightly stretch or distort the paper,
exacerbating the later effects of framing or high humidities. I
gather the base collotype image was over printed using silk screens.
Most screen printing inks in the seventies were solvent based, so I
would not expect the adherence of screen printing inks to the
collotype base layer to be suspect.

In screen printing, the colour characteristics (intensity,
transparency, etc.) of each ink laydown are controlled by the
thickness, hole size, and profile of the screen fabric, in addition
to the density and characteristics of the pigment in the medium, and
to a lesser extent by the squeegee shape, angle, and pressure. A
very pale or translucent colour may be created with a thick laydown
of very transparent ink. The intensity of colour in a layer of ink
(eg a "wash" vs a "solid") has little bearing on whether you will
find a screen pattern upon close examination.

Every shop developed its own methods: I often mixed my own inks, by
adding pigments to commercial screen printing base, thickeners and
solvents. This allowed me to use a wider colour range and
non-fugitive pigments--better, I could create very transparent
layers. My early attempts at mixing my own inks were done using
painter's oil colours as my source. Later, I used offset printer's
inks (denser pigment and more finely ground), and finally found a
source of pre-ground pigments that could be mixed directly into my
screen printing ink media. Many other screen printers in the sixties
and seventies were using similar oil-based pigments to colour their
inks, and the migration of the suspended oil might be a source of
the "pooling" in the margins. I should also point out that an
accidental "pool" of ink at a corner of a print outside of the image
is not an uncommon occurrence.

My job as a master printer was to make manifest the intentions of
the artists I worked with. I also had a responsibility to advise on
the permanence of the materials (to the best of my knowledge), but I
learned that my artists were usually more excited by the process of
creating an "interesting" work of art. In the heat of working on an
exciting project, print longevity can be low on your list of
priorities.

While examining a low resolution image of the print, I noted that
the commentary accompanying the image says "Materials: Screenprint
on collotype, with collage". No use of collage was mentioned in the
rather comprehensive article I read describing Hamilton's
printmaking, and none in Ms Ellis' description of the work. However,
considering Halmilton's reputation as an adventurous printmaker, I
wonder if the cracking or delaminating are related to the reference
to "collage".

Jerry Shiner
Keepsafe Microclimate Systems


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                  Conservation DistList Instance 22:12
                 Distributed: Saturday, August 23, 2008
                       Message Id: cdl-22-12-002
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