Vermeer's Palette: Smalt

Origin, History and Characteristics

(Smalte, smaltino, starch blue, cobalt glass)

Smalt is ground blue cobalt-containing glass. It was first described by Borghini in 1584. Cobalt oxide obtained was melted together with quartz and potash or added to molten glass. When poured into cold water, the blue melt disintegrated into particles which were then grounded. Several grades of smalt were made according to cobalt content and grain size. In European painting it was initially used as a substitute for expensive natural ultramarine, although it is much less bright. Smalt has been historically important as a pigment in painting, pottery, for surface decoration of other types of glass and ceramics, and other media (fig. 1). It is colored to a deep powder blue hue using cobalt ions derived from cobalt oxide. In the sixteenth century, the Erzgebirge mountains were mined for mineral ores of cobalt and antimony that were used to make the blue pigment smalt, a potash glass, as well as yellow pigments based on lead-antimony oxides.

As smalt is a glass, its particles are transparent, and its covering power as a pigment for fine painting is low. Therefore it must be coarsely ground for use as a pigment. When used in oil medium, it has a tendency to settle under the paint film (causing it to yellow in time) and streak down perpendicular surfaces. Smalt was frequently bound with a protein binding medium (usually parchment or animal skin glue) as stated in several contemporary treaties to prevent it from being altered by the yellowing of the oil film. The gelatinous nature of the glue medium keeps the particles suspended until the paint becomes dry. Although smalt is known to fade, the degree to which this occurs can vary even within the same painting.

"Our appreciation of the wide range of uses of smalt is hindered by its having deteriorated over time. The skies in paintings by the Venetian artist Paolo Veronese have turned greyish. The blue robe worn by the Virgin in Tintoretto’s Madonna of the Stars has lost its blue color and become brownish.Unfortunately, the smalt Rembrandt used has decayed and the paint has become a turbid brownish color; backgrounds and curtains in his paintings are now dingy looking, but must once have been quite blue."^{Barbara H. Berrie, "Mining for Color: New Blues, Yellows, and Translucent Paint," Early Science and Medicine 20, no. 4-6 (2015): 308-334, https://doi.org/10.1163/15733823-02046p02.}

LOOKING OVER VERMEER'S SHOULDER

The complete book about Johannes Vermeer's and 17th-century fine-painting techniques and materials

by Jonathan Janson | 2020

Enhanced by the author's dual expertise as both a seasoned painter and a renowned authority on Vermeer, Looking Over Vermeer's Shoulder offers an in-depth exploration of the artistic techniques and practices that elevated Vermeer to legendary status in the art world. The book meticulously delves into every aspect of 17th-century painting, from the initial canvas preparation to the details of underdrawing, underpainting, finishing touches, and glazing, as well as nuances in palette, brushwork, pigments, and compositional strategy. All of these facets are articulated in an accessible and lucid manner.

Furthermore, the book examines Vermeer's unique approach to various artistic elements and studio practices. These include his innovative use of the camera obscura, the intricacies of his studio setup, and his representation of his favorite motifs subjects, such as wall maps, floor tiles, and "pictures within pictures."

By observing closely the studio practices of Vermeer and his preeminent contemporaries, the reader will acquire a concrete understanding of 17th-century painting methods and materials and gain a fresh view of Vermeer's 35 masterworks, which reveal a seamless unity of craft and poetry.

While the book is not structured as a step-by-step instructional guide, it serves as an invaluable resource for realist painters seeking to enhance their own craft. The technical insights offered are highly adaptable, offering a wealth of knowledge that can be applied to a broad range of figurative painting styles.

LOOKING OVER VERMEER'S SHOULDER
author: Jonathan Janson
date: 2020 (second edition)
pages: 294
illustrations: 200-plus illustrations and diagrams
formats: PDF
$29.95

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CONTENTS

1. Vermeer's Training, Technical Background & Ambitions
2. An Overview of Vermeer’s Technical & Stylistic Evolution
3. Fame, Originality & Subject Matte
4. Reality or Illusion: Did Vermeer’s Interiors ever Exist?
5. Color
6. Composition
7. Mimesi & Illusionism
8. Perspective
9. Camera Obscura Vision
10. Light & Modeling
11. Studio
12. Four Essential Motifs in Vermeer’s Oeuvre

13. Drapery
14. Painting Flesh
15. Canvas
16. Grounding
17. “Inventing,” or Underdrawing
18. “Dead-Coloring,” or Underpainting
19. “Working-up,” or Finishing
20. Glazing
21. Mediums, Binders & Varnishes
22. Paint Application & Consistency
23. Pigments, Paints & Palettes
24. Brushes & Brushwork

Smalt was frequently used by painters in the blue skies and distant mountains. It was popular for its low cost and its manufacture became a specialty of the Dutch and Flemish in the seventeenth century. Smalt is a very good dryer and was admixed in small quantities to dry other slower drying pigments.

Smalt in Vermeer's Painting

In several early paintings by Vermeer smalt was found, but mostly as an admixture to other pigments in deep layers. The smalt found in Vermeer's paintings is very coarse grained. There is smalt in the lighter area of the wallsof A Maid Asleep (fig. 2) together with azurite, ocher, brown ocher and naturally the principal component, white-lead and in the underpainting of the blue area of the carpet. An upper area contains instead, azurite and natural ultramarine. Smalt may also be found in The Procuress in both the light white areas and as a component of the green paint with lead-tin yellow.

There is extensive use of smalt in Diana and her Companions in the brown undermodeling where it is bound in a protein medium, it is also in the flesh tones as well as in the thistle, the rock and the dog's white fur.

In a few of his earlier works Vermeer used small quantities of smalt to tone down the white areas of pure white instead of black which produces a sullen matt gray effect. The artist later used natural ultramarine for the same purposes in works such as the Young Woman with a Water Pitcher.

Vermeer seems to have abandoned smalt after the first few early works along with complex mixtures of five or more pigments.