Rob Hunter passed along the postings on Patricia Frazzi’s inquiry asking of
any publications dealing with the chemical composition of clay and glaze of
English creamware, pearlware and whiteware and some of the responses to that
inquiry. I very much agree with Mary Beaudry, Tim Scarlett and Rob that the
analysis that Ms. Frazzi is thinking about undertaking would be difficult and
fraught with problems. Most likely the effort would not be worth the
resulting information and this would be a very time consuming project. Here are
some of the problems involved in such a study.
1. All three of these “wares” evolved over time and the mix of clays
and the constituents of the glazes also went through changes. I.e. creamware,
pearlware and whiteware are not fixed types and the sherds one chooses to
use for testing may not be very representative of the range of formulas for the
variety of wares that archaeologists have classified as these wares. For
example Mellany Delhome found six different formulas for Wedgwood’s “pearlware
/ pearl white” dating from 1815 to 1846 (Miller 1980:16-17). Apparently
she was not able to find the formula for the 1779 version of “Pearl White” or
those that may have come in between the earliest version and the types made
after 1815.
One can gain some idea of the complexity of this subject by looking at the
formulas that have been published in the following references.
Lakin, Thomas
1824 Valuable Receipts of the Lat Mr. Thomas Lakin, with Proper and
Necessary Directions for their Preparations and Use in the Manufacture of
Porcelain, Earthenware, and Stone China. Privately Published, Leeds, England.
Evans, William
1846 Art and History of the Potting Business, compiled from the most
practical Sources for the Especial use of Working Potters. Reprinted in the
Journal of Ceramic History No. 3, 1970, edited by A. R. Mountford.
Shaw, Simeon
1837 The Chemistry of the Several Natural and Artificial Heterogeneous
Compounds used in Manufacturing Porcelain, Glass and Pottery. 1900 reprint by
Scott, Greenwood and Co. London.
The above references provide a great many receipts for clay bodies and
glazes. Creamware is usually listed as CC ware. Pearlware is not listed in any
of the formulas that I have seen. The main clue would be the listing of
cobalt as a tint for the body or the glazes. Glazes and bodies are listed under
such heading as “for blue printed ware” or “for edged ware.” A number of
bodies could be mixed with a number of glazes for the same visual effect, i.e.
a blue tinted ware or a very white ware. How would one know which formula
was being used for the sample being subjected to chemical analysis?
2. Selection of which sherds to use would be difficult because creamware is
rarely marked. Printed pearlware and whiteware vessels do often have maker’
s marks, but the most common marks are for potters that were in business for
long periods of time, which makes it difficult to have a tightly dated
sample to work with.
3. The intent of the potter in producing the ware is up to interpretation.
What is pearlware to you may be my china glaze or what someone else would
call whiteware. Cobalt can be used in combination with decoration to
produce an imitation of Chinese porcelain i.e. China glaze ware, or it might be
used as a whitening agent to make a whiter looking ware. In these cases, one may
still see some bluing in the areas where the glaze is thicker like around
footrings. The cobalt may be used to tint the body or the glaze or both.
Pearlware is a pigment of our imagination. For further discussion of this see
the following sources.
George L. Miller
1980 Classification and Economic Scaling of Nineteenth Century Ceramics.
Historical Archaeology. 1980 Vol 14:1-40 Appendix A Part 1, Pearlware in the
19th Century, pp 15-18.
George L. Miller and Robert R. Hunter
2001 How Creamware got the Blues: The Origins of China Glaze and
Pearlware. Ceramics in America 2001. pages 135-161. Chipstone Foundation, edited
by Robert Hunter. As mentioned earlier, this can be down loaded from the
Chipstone web site.
George L. Miller and Amy C. Earls
2008 War and Pots: The Impact of Economics and Politics on Ceramics
Consumption Patterns. Ceramics in America 2008. pages 67-108. Chipstone
Foundation, edited by Robert Hunter.
The 2008 volume of Ceramics in America, as Rob mentioned in an earlier
posting, will be available shortly and has a number of important articles on the
ceramics trade and American stoneware.
George L. Miller
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