Gamblin Conservation Colors

Ulrik Runeberg <rune-ulrik [at] gmx__de> writes

>My general impression is that certain colours work better than
>others: Burnt Sienna, for instance, represented an inpainting colour
>with similar characteristics to oil colour, and only after being
>diluted several times with pure gum spirits of turpentine, a glossy
>brilliance appeared which made further retouchings impossible due to
>the shininess of the retouching medium. On the other hand I observed
>that such pigments as Venetian Red possess that glossiness right
>from the beginning, before even being diluted. This brilliance even
>could not be reduced after stirring the colour well.
>
>As I never have used a set of Gamblin Colours before, I wonder
>whether the differences of the various colours is an exception. Who
>could share any similar experience, and provide possibly any
>solution of the described problem? I also welcome any further
>suggestion in regard of modifying and applying Gamblin (possible
>solvents, isolating coatings, e.g.).

I helped with the development of the Gamblin colors and teach
workshops about varnishes and retouching with Gamblin colors and
these questions frequently come up. The Gamblin Conservation Colors
are mixed in a stable, reversible aldehyde resin, Laropal A-81 made
by BASF. Just as with oil colors and other resin based retouching
paints (Maimeri, Charbonnel) a different amount of binder is used
with each pigment. Some colors require more binder, others less.
This will result in varying gloss and textures. This is why you
often need to add a bit of resin to some colors. Of course it will
depend on the gloss of the surface you are trying to match as to
whether you will need to add resin.

People often use the colors "wet" out of the jar and I find it works
much better to set a little dab of each color out on a palette and
let them dry. You use much less paint with this technique.
Isopropanol works very well as a diluent. Many other solvents can be
used including high aromatic white sprits (approximately 40%
aromatic) and solvent mixtures but isopropanol works well most of
the time. In our studio we use small vials of isopropanol to wet the
brush and Laropal A-81 in isopropanol to add gloss. It is not
necessary to to stir the paint in the jars. We intentionally dip out
the thicker parts of the pigment paste and leave the separated resin
in the jar. Sometimes solvent (isopropanol) needs to be added to the
jars to moisten the paints.


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                  Conservation DistList Instance 18:16
                Distributed: Tuesday, September 28, 2004
                       Message Id: cdl-18-16-002
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