4
Just as we cannot extrapolate to the whole painting from media analysis in
one color area alone, documentary sources indicate that the medium could
change not only from color to color, but also from paint layer to paint layer.
Once again, this was not confined to the nineteenth century. Marshall Smith
instructed that lead white be mixed with nut oil, but noted that linseed oil
could be used in dead-coloring (16). Advice to vary the medium according
to the layer continued to appear in the literature, the faster-drying linseed oil
again being recommended fo r underlayers such as dead coloring, with poppy
or nut oil in the finishing layers (17).
Interestingly, the medium fo r the first lay or dead coloring need not have
been oil at all. There were references to the use of watercolor, egg tempera,
and a combination of two-thirds starch to one-third oil (18).
Contemporary experience with oil painting materials may also lead to as
sumptions that require examination. To day, if we wish to prepare a "tradi
tional" lead-white ground, the first step would be to size the canvas using a
hide glue such as rabbit-skin or parchment size. Although there are indications
that the use of glue size, including isinglass, was common in the past, this was
not the only material used. Starch was also employed as a size layer and
appears in recipes throughout the nineteenth century. There were also indi
cations that the addition of a plasticizer or humectant such as honey, sugar,
or glycerine would not have been unusual. Near the end of the century, we
find a reference to the use of collodion (cellulose nitrate) as a replacement
fo r the size layer (19).Our present-day lenses can also result in our underestimating the importance
of materials that in our own day are no longer in use or have become precious
and rare. Isinglass, a glue prepared from the swim bladder of the Russian
sturgeon, is not widely available today. In eighteenth-and nineteenth-century
England, isinglass was commonly used fo r a variety of purposes: to clarifY
beer, wine, and soup, and as a sizing agent fo r fabric, ribbons, and paper.
Therefore, the presence of what is now quite rare, but was then a relatively
commonplace glue in the size layer fo r an oil painting, is not surprising.
Another such material that has dropped out of use entirely is sugar of lead
(lead acetate). A white crystalline powder widely used as a drier fo r oil paint,
it was added directly to the pigment-oil mixture and was also present in
medium recipes. Lead acetate could be purchased easily from apothecaries
and appears to have been in wide use by painters in the late eighteenth and
nineteenth centuries. By the twentieth century, however, it was never men
tioned in sources on oil painting materials and techniques, although other
traditional lead driers, such as litharge or metallic lead, do receive notice. As
a result, the important role that this material played has never been acknowl
edged or studied in the twentieth century.Conclusion
Although we must accept Lowenthal's observation that life in the past was
"based on ways of being and believing incommensurable with our own," we
should not see the exercise of studying past practices and materials as fu tile
(20). Rather, we should equip ourselves with the knowledge that we are
handicapped by our late twentieth-century standpoint. By making use of a
variety of disciplines, by not concentrating our energies too much on only
one avenue of inquiry, we can continue the search to "know all." As much
as possible, we should look outside of our immediate disciplines fo r research
ers who are also mining the past, as it is this multidisciplinary approach that
will enrich our understanding and interpretation of the "facts."Notes
- Forester, Sir Archibald. 19 90. Sponsor's preface. In Art in the Making: Impression
ism, D. Bomford,]. Kirby,]. Leighton, and A. Roy. London: The National Gallery
and Yale University Press.
Historical Painting Tech niques, Materials, and Studio Practice