pigmented colorants: dependence on media and time - Cornell ...

and reasonable cost. It is extremely inert and unaffected by very harsh conditions.
Titanium pigments are dense and heavy, and have great hiding power.
5.1.3 Media
In our research we also studied the effects of many various media on the chosen
pigments. Each binder imparts its own characteristic optical and textural qualities,
as well as maintaining a specific tactile behavior while working. Many different
binding media have been discussed in detail in Chapter 2.
To accurately compare different types of binding media, it was necessary that
all of the considered media be able to be applied in a similar fashion to a con-
sistent support. Typically, this is not a concern as most media can be applied to
the same types of supports–whether it is canvas, panel, or heavy weight paper.
Unfortunately, fresco painting does not fit the stereotypical type for binder, as it
is applied directly to masonry. Thus, we were unable to study fresco in this work,
as creating many small samples of this material would have been too difficult.
Descriptions of the eight binding materials we studied, including more specific
details on their composition follow:
Acrylic. The specific acrylic polymer emulsion used was Acrylex Thick Medium
#33 from Pearl Paint (New York). The medium is reasonably thick by itself and
is considerably opaque while wet. If desired, the medium can be thinned with
water to improve handling. One must keep brushes wet as the binder dries to a
waterproof film. The translucency increases upon drying.
Casein. Rather than casein powder, premixed borax-hydrolyzing casein from
Schmincke (Erkrath-Unterfeldhaus, Germany) was used. For painting, the direc-
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tions called for the medium be thinned 1:1 with water, though in practice this