Historical Painting Techniques, Materials, and Studio Practice

Abstract

The discovery of three "new" pig­
ments is described. Their history is
traced through the literature of pig­
ments, ceramics, and glass. Tin white,
previously undiscovered, is followed
from Iraqi ceramics to its occurrence
as a pigment on Jain miniatures in
India. Burnt green earth, mentioned
by early Italian and nineteenth-cen­
tury English writers, is identified on
nineteenth-century oil paintings.
Cobalt oxide colorant is followed
from Persia to Europe and China
and finally, in a new form, to Vene­
tian enamels and as smalt on Hindu
miniatures.

70

Connections and Coincidences: Three Pigments

Josephine A. Darrah

Science Group

Conservation Department

Victoria & Albert Museum

London SW7 2RL

United Kingdom

Introduction

There are certain advantages in being a generalist rather than a specialist. In

this paper, the author hopes to show some of the connections and coinci­

dences that occur when a wide range of materials and objects are analyzed

in the same laboratory.

Tin white

The pigment known as tin white is elusive. It is mentioned occasionally in

medieval and later European literature, but has never been identified on paint­

mgs.

Tin oxide was used first as an opacifier in ceramic glazes to reproduce Chi­

nese porcelains in ninth-century Iraq. From there it spread throughout the

Near East (by the tenth century) and to Spain (by the thirteenth century) via

North Africa (1). By the twelfth century it was being used to opacifY glass.

It has been identified in twelfth-century Byzantine colored mosaic tesserae

in Tchernigov, Ukraine (2). In 1612, in the first book devoted to glassmaking,

Neri describes the preparation of enamel by adding calcined tin to calcined

lead (3). The earliest dated European tin white glass is late fifteenth-century

Venetian (4). White glass and enamel of the succeeding centuries is almost

always opacified with tin (5).

Writing in the late thirteenth century, Eraclius gives two very similar recipes

fo r white glaze used fo r earthenware (6). White glass was ground very finely,

mixed with sulfur, painted onto the ceramic and fired. Tin is not mentioned

but must have been the opacifier. The purpose of the sulfur is not known. It

would not have survived the firing.

The Paduan manuscript written in Venice in the seventeenth century (but

copying sixteenth-century material), has another similar recipe, but here it is

fo r a pigment: "Un bianco bellissmo-Si piglia cristallo di Venetia ... " [take

some powdered Venice glass, add to it a third part of powdered sulfur] (7).

The mixture was heated to red heat in a pipkin, cooled, and ground. Mer­

rifield suggests that it was used fo r painting miniatures (8).

Harley quotes an English source (ca. 1500): "For to make Ceruse. Take plates

of tinne and beate them as thinne as thowe maist ... " (9). The tin was hung

in a sealed barrel with vinegar fo r several weeks. The method is exactly the

same as that used to produce lead or flake white. Indeed, the name ceruse

was applied in England to both tin and lead white, and perhaps more correctly

to a mixture of lead white and chalk.

Harley says that documentary sources indicate that tin white was used in

manuscripts. Her suggestion that it became obsolete because manuscript il­

lumination declined cannot be substantiated, as the pigment has not been

identified in any English or European miniatures. In the seventeenth century,

Van Dyck tried it in oil and reported that it had insufficient body and was

only useful fo r manuscript illumination (10). My tens fo und that it blackened

in sunlight, spoiled white lead if the two were mixed, was useless in oil, and

also in distemper if exposed to air (11). In the late eighteenth century, France

Guyton de Morveau experimented with pigments and reported that tin white

was unsuitable as it tended to yellow or blue (12).

Historical Painting Techniques, Materials, and Studio Practice