Historical Painting Techniques, Materials, and Studio Practice

process described by Cennini fo r gesso sottile as furnishing the best ground
fo r gilding (29). In fa ct, Cennini describes in Chapter CXVIII how certain
panels can be grounded only with gesso sottile.

Conclusion

Finally, returning to the meaning of the giesso volteriano in Cennini's text,
we presume that the material must have been calcium sulfate dihydrate
burned at 300-650 °c, thus fo rming soluble anhydrite, which was used fo r
the gesso grosso. The preparation of the gesso sottile would be a process of
changing the chemical composition, altering the texture, and washing.
The author does not agree with the point of view put fo rward by E. Martin,
et al. that Cennini did not know whether the giesso volteriano he discussed
was unburned gypsum directly from the quarries of Volterra or if it was
processed by being burned (30). Cennini must have had a good understanding
of these materials. That we do not understand the exact meaning of his words
600 years later is another matter. In his own time and geographical sphere, it
was most likely very well understood, at least by other craftspersons.

Acknowledgments

It was extremely difficult to obtain raw calcium sulfate dihydrate in Denmark. I am

very much indebted to the following persons who made the practical experiments

possible: V Meyer (Building Materials, Kalkbr;enderihavnsgade 20, 2100 Copenha­

gen), who readily took the trouble to import unburned gypsum for my research

purposes, and to Niels Erik Jensen (CTO, Aiborg Portland, 9220 Aiborg 0st), who

demonstrated a keen interest and readiness to help with this project by providing me

with raw gypsum in various forms. I wish to thank my colleague, chemist Mads Chr.

Christensen (School of Conservation, Copenhagen) for his help in carrying out the

analyses, and for fruitful discussions. My colleague, geologist Nicoline Kalsbeek,

(School of Conservation), has kindly furnished me with information from the Cam­

bridge Structural Database. Finally, I wish to thank Professor Bo Ossian Lindberg

(Institutionen fOr Konstvetenskap, University of Lund, Sweden) for reading and com­

menting on the text.

Notes

1. Cennini, C. 1960. The Craftsman's Handbook: II libro de/l'arte. Translated by D. V
   Thompson, Jr.. New York, Dover Reprint (Yale University Press, 1933).


2. Cennini, C. Boken om nullarkonsten. Oversiittning och notkommentar av Ossian Lind­
   berg. Unpublished manuscript provided by Professor Lindberg. Part of the text
   has been published in Lindberg, B. 0. 1991. Antologi om milleriteknik. Lund: In­
   stitutionen fo r Konstvetenskap, Lunds Universitet. As shown by Lindberg, the
   Codex Laurentianus (Florence, Biblioteca Laurentiana, MS 78 P 23) must be con­
   sidered closest to the lost original manuscript. The Codex Riccardianus (Florence,
   Biblioteca Riccardiana, MS 2190), however, is our only source for several passages
   which are missing in the Laurentianus text. Therefore, Lindberg based his edition
   on both the Laurentianus and the Riccardianus codices, as Thompson also did.
   For the discussion of the surviving transcripts of Cennini's text and the various
   editions and translations, see Lindberg, B. 0. 1991. Cennino Cennini: den obnde
   masteren. In Miliningens anatomi. Exhibition catalogue. Kuituren, Lund, 39-48.


3. Od dy, W A. 1981. Gilding through the ages: An outline history of the process
   in the Old World. Gold Bulletin and Gold Patent Digest (14): 75-79, in particular
   page 77. See also, Gilded wood: conservation and history. 1991. Gilding Conser­
   vation Symposium, Philadelphia Museum oj Art. Madison, Sound View Press, 34.


4. Berger, E. 1973. Quellen und Technik der Fresko-, Oel-und Temperamalerei des Mit­
   telalters. Liechtenstein Sandig reprint (Munich 1912),13.


5. The medieval sources mentioning the preparation of grounds also mention (an­
   imal) glue as the medium. The only exception, to my knowledge, is the fifteenth­
   century Bolognese manuscript, which mentions a ground that apparently has no
   medium but depends on the setting with water of the hernihydrite. See Mer­
   rifield, M. P 1849. Segreti per colori, Original treatises on the arts oj painting,
   Vol. II. London, John Murray, 595.


6. Martin, E., N. Sonoda, and A. R. Duval. 1992. Contribution a l'etude des pre­
   parations blanches des tableaux italiens sur bois. Studies in Conservation (37): 82-

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