|
Umber is a natural brown or reddish-brown earth pigment that contains iron oxide and manganese oxide. It is darker than the other similar earth pigments, ochre and sienna.〔''Shorter Oxford English Dictionary'', Fifth Edition, Oxford University Press, 2002. "A red brown earth containing iron and manganese oxides and darker than ochre and sienna, used to make various pigments."〕 In its natural form, it is called raw umber. When heated (calcinated), the color becomes more intense, and the color is known as burnt umber. The name comes from ''terra di ombra'', or earth of Umbria, the Italian name of the pigment. Umbria is a mountainous region in central Italy where the pigment was originally extracted.〔''Shorter Oxford English Dictionary'', Fifth Edition, Oxford University Press, 2002.〕 The word also may be related to the Latin word ''Umbra''.〔(Blick Art Materials, 00501-8054 — Burnt Umber )〕 Umber is not one precise color, but a range of different colors, from medium to dark, from yellowish to reddish to grayish. The color of the natural earth depends upon the amount of iron oxide and manganese in the clay. Umber earth pigments contain between five and twenty percent manganese oxide, which accounts for their being a darker color than yellow ochre or sienna.〔 p. 30〕 Commercial colors vary depending upon the manufacturer or the color list. Not all umber pigments contain natural earths; some contain synthetic iron and manganese oxide, indicated on the label. Pigments containing the natural umber earths indicate them on the label as PBr7 (Pigment brown 7), following the Colour Index International system. The color shown in the box at right is one of the many commercial varieties of umber, from the ISCC-NBS color list: (ISCC-NBS Dictionary of Color Names (1955)--Color Sample of Umber (color sample #61) ). File:LimoniteUSGOV.jpg|Limonite, or hydrated iron oxide, is the basic ingredient of the earth pigments ochre, sienna and umber. File:ManganeseOreUSGOV.jpg|The presence of a large amount of manganese makes umber earth colors darker than ochre or sienna. File:Terra ombra naturale umber.jpg|The pigment known as raw umber or natural umber came originally from Umbria, in Italy. File:Terra ombra naturale.JPG|Another sample of natural umber pigment, from the Italian Wikipedia. ==History== Umber was one of the first pigments used by man; it is found along with carbon black, red and yellow ocher in cave paintings from the neolithic period. Dark brown pigments were rarely used in Medieval art; artists of that period preferred bright, distinct colors such as red, blue and green, rather than colorless colors. The umbers were not widely used in Europe before the end of the fifteenth century; The Renaissance painter and writer Giorgio Vasari (1511-1574) described them as being rather new in his time.〔Daniel V. Thompson, (1956), ''The Materials and Techniques of Medieval Painting'', p. 88-89〕 The great age of umber was the ''baroque'' period, where it often provided the dark shades in the chiaroscuro (light-dark) style of painting. It was an important part of the palette of Caravaggio (1571-1610) and Rembrandt (1606-1669). Rembrandt used it as an important element of his rich and complex browns, and he also took advantage of its other qualities; it dried more quickly than other browns, and therefore he often used it as a ground so he could work more quickly. or mixed it with other pigments to speed up the drying process.〔http://www.webexhibits.org/pigments/indiv/overview/umber.html Webexhibits- Pigments through the Ages.〕 The Dutch artist Johannes Vermeer used umber to create shadows on whitewashed walls that were warmer and more harmonious than those created with black pigment. In the second half of the 19th century, the Impressionists rebelled against the use of umber and other earth colors. Camille Pissarro denounced the "old, dull earth colors" and said he had banned them from his palette.〔http://www.webexhibits.org/pigments/intro/industrialization.html Web-exhibits- Pigments through the ages.〕 The impressionists chose to make their own browns from mixtures of red, yellow, green, blue and other pigments, particularly the new synthetic pigments such as cobalt blue and emerald green that had just been introduced. In the 20th century, natural umber pigments began to be replaced by pigments made with synthetic iron oxide and manganese oxide. Natural umber pigments are still being made, with Cyprus as a prominent source. Pigments containing the natural earths are labeled as PBr7, or Brown pigment 7. File:Caravaggioapollo.jpg|The Italian baroque painter Caravaggio used umber to create the darkness in his chiaroscuro ("light-dark") style of painting. File:Johannes Vermeer - Het melkmeisje - Google Art Project.jpg|The ''milkmaid'', by Johannes Vermeer (1650). Vermeer used umber for the shadows on the whitewashed walls, since they were warmer than those made with black. File:Rembrandt self portrait.jpg|Self portrait by Rembrandt van Rijn (1659). Rembrandt used umbers to create his rich and complex browns, as a ground, and to speed the drying of his paintings. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Umber」の詳細全文を読む スポンサード リンク
|