A
Abstract art An art form which is not dependent upon a fundamentally naturalistic approach to the subject matter for the expression of form, space and color.
Abstract Expressionism A form of abstract art which originated in America in the 1950s in which the artist involved chance and the subconscious in the creation of the oil painting.
Alla prima An Italian term meaning at first, a technique in which the artist works directly on the surface without preliminary under-painting or drawing.
Arriccio A rough plaster surface consisting of lime and sand mixed in water. This is applied to a wall in the initial stages of fresco painting.
Azurite A blue mineral derivative of copper often substituted for the very expensive ultramarine.
Alizarin A reddish purple pigment obtained from the root of the madder plant. Combined with salts of metals it creates the lake colors.
B
Baroque A style of architecture, painting and sculpture which originated in Europe in the late sixteenth century and which lasted until the eighteenth. The movement succeeded Mannerism and turned away from the straight line and reason, in favor of curves. emotion and un-idealized naturalism. Caravaggio, Rubens, Rembrandt and Velazquez represent different strains of Baroque art.
Bitumen (asphaltum) This transparent rich brown pigment never dries completely and causes deterioration and craquelure if used in under-painting. It was used, with frequently disastrous results, in the late eighteenth and nineteenth centuries. Rembrandt, amongst others, used it as a glaze, for which it is suitable.
Bladders Before the invention of metal tubes for artists’ colors. leather bladders were used for storing oil paint. These were pricked by the artist when the oil paint was needed and then resealed to keep the oil paint fresh.
Blocking-in An under-painting technique by which the artist roughly describes the forms and composition of an oil painting.
Blue Rider (Der Blaue Reiter) An influential group of German Expressionists formed in Munich in 1911 bv Wassily Kandinsky, Paul Klee, August Macke and Franz Marc.
Broken color A term covering a number of techniques in which several colors are used in their pure state rather than being blended or mixed. Usually the oil paint quality is stiff and thick and, when the oil paint is dragged across the surface, layers beneath show through. This term can also refer to the Pointillist technique.
C
Cadmiums Brilliant permanent pigments which are suitable for most techniques. Cadmiums turn black when mixed with copper colors, such as emerald green and brown when mixed with lime. The colors include cadmium yellow, green and red. The latter is considered the best substitute for vermilion.
Camera obscura A technical aid, widelv used in the seventeenth and eighteenth centuries, which consisted of a darkened box or tent containing lenses and a mirror. The artist could project the image of an object or landscape onto the oil painting surface and then trace it out in charcoal or graphite.
Casein A strongly adhesive substance made from the curd of fresh milk.
Cennini, Cennino A fifteenth century Florentine painter best known for his book Libro delI’arte (The Craftsman’s Handbook). Written c.1390, it contains valuable information on early tempera and fresco techniques.
Chiaroscuro The literal translation of this Italian term is lightdark but the term has come to mean the skilful exploitation of light and shadow within an oil painting. Rembrandt and Caravaggio are the artists particularly associated with the use of chiaroscuro.
Chrome yellow A brilliant color, chrome yellow is made from lead chromate. It covers and dries well but tends to change tone with time.
Classicism The term given to a style of art which is ultimately derived from the study of Greek and Roman’ artists. Classicism is often considered the antithesis of Romanticism.
Collage Derived from the French verb coller meaning ‘to stick’, collage is the technique of pasting cloth, paper or other materials onto a canvas or surface. It was first used by the Cubist artists.
Craquelure This is the term used to designate the tiny cracks and fine lines covering the surface of most old oil paintings. They are caused by the shrinking and movement of the ground and the oil paint surface.
Cross-hatching A technique in which oil paint or another medium is laid down or drawn in a series of criss-crossing strokes to build up depth and tone.
Cubism An innovatory and influential abstract art movement begun in Paris around 1907 by Picasso and Braque. As a reaction against previous naturalistic oil painting traditions, the Cubists simultaneously depicted many different views of an object. They often represented forms as superimposed geometric planes with the intention of expressing the idea of an object rather than any particular aspect.
D
Distemper An impermanent type of paint in which the pigments are mixed with size.
E
Emerald green This very poisonous color derived from copper arsenate will turn black if mixed with sulphur pigment. The Old Masters were aware of this danger and thus over-painted emerald green with varnish.
Encaustic A technique in which molten wax, mixed with pigments and sometimes resin, is applied to a surface. When dry, the colors have a glossy shine. This technique was most used in the first and third centuries but has more recently been adapted by artists such as Jasper Johns.
Expressionism A term applied to an art movement, founded in the twentieth century, which opposed the imitation of nature and Impressionism. Expressionists tend to stress emotion and feeling with strong color and line. Van Gogh is considered the great forerunner of Expressionism.
F
Fat over lean An oil painting technique which allows the bottom layer of oil paint to dry before further application. ‘Fat’ painted is mixed with oil to create a thick paste while ‘lean’ paint is thinned with a diluent such as turpentine to make it dry more quickly.
Fauvism An art movement in the early twentieth century whose main exponent was Matisse. A group of artists, including Matisse. exhibited at the Paris Salon show of 1905 and were nicknamed les Fauves or ‘the wild beasts’ as their works were full of distortion, pure color and frenzied brushstrokes.
Fete galante A term first used in. the eighteenth centurv to describe a n oil painting of a dreamlike pastoral setting which shows people, often in extravagant costume, amusing themselves with dancing, music-making and courtship. Watteau is referred to as a painter of ‘fetes galantes’.
Florentine School From the thirteenth century, the Florentines held a prominent position in the art world. They were particularly concerned with problems of design and their approach to art was scientific and intellectual. Giotto and Leonardo are among the many artists that Florence ‘ produced.
Fresco A method of wall-painting on a plasterground. Buon fresco, or true fresco, was much used in Italy from the thirteenth to the sixteenth centuries. First, the arriccio is applied and upon this the design, or sinopia, is traced. An area. small enough to be completed in one day – the giornata – is covered with a final layer of plaster, the inionaco. The design is then redrawn and painted with pigments mixed with water. Fresco secco is painting on dry plaster and suffers, like distemper, from impermanence.
Fugitive color A phrase used to describe a pigment’s impermanence and tendency to fade or change color under the influence of natural effects such as sunlight.
G
Gamboge A gum resin often used in watercolor. If applied in thick layers, it creates a gloss finish but it is not considered suitable for oil paint colors.
Genre painting A type of art which depicts scenes from everyday life. Two of the better known genre painters are the Dutch artist Vermeer and the Spaniard Velazquez.
Gesso A white, absorbent ground used in tempera and oil painting. In Italy during the early Renaissance, panels were first prepared with several coats of gesso grosso which is gesso mixed with size. On top of this coarse gesso was laid a coat of gesso sottile. This plaster and size mixture was brilliant white and gave a smooth surface.
Giornata A name given to an area in fresco painting which can be completed in one day.
Glazing An oil painting technique by which thin, transparent layers of oil paint are applied over an opaque layer to modify that layer’s color. It is sometimes difficult to determine exactly the glazes used by the Old Masters because of previous restoration or cleaning, and also because of the similarity between the appearance of a glazed paint layer and varnish.
Gouache An opaque, water-based paint in which the pigments are bound with glue.
Green earths These colors are similar to ochre and are among the oldest known painting colors. They were important in the Middle Ages and early
Italian painting as middle and shadow tones in flesh.
Ground A ground is used to provide a satisfactory painting surface. In oil painting, the ground is usually either an oil-based mixture or, more commonly, gesso. The ground must not be too absorbent, and it must be durable and not crack. Grounds may also be tinted to give a painting more color.
Gum arabic Gum obtained from the acacia plant. It is used as a binding agent in watercolors, gouache and pastels.
H
Hessian A type of canvas which generally has a coarse, thick weave.
I
lmpasto Oil paint which is applied very thickly. When the oil paint is thick enough to create lumps or reveal distinct brush strokes, it is said to be heavily impasted.
Impressionism A loose association of painters formed in Paris in 1874 for exhibiting purposes and as an alternative to the dry, academic Salon school. Monet, Renoir and Pissarro, amongst many others, depicted the natural, atmospheric effects of light in nature by painting out-of-doors in broken colors. They also painted shadows of objects in complementary colors. The impressionist color theories have influenced all sub-sequent art movements.
Infra-red photography A method of photography which can be used to examine thinly applied paint layers in an oil painting. The infra-red waves, which lie beneath the red end of the visible spectrum, penetrate the layers and can sometimes reveal the artist’s original drawing.
Intonaco A smooth layer of fine plaster which is placed on top of the arriccio in fresco.
L
Limning An archaic term meaning to draw or paint. Used particularly with reference to manuscript illumination and miniature painting.
Lining A conservation term for placing a new canvas on the back of a deteriorating original oil painting.
Linseed oil An oil, derived from the flax plant, which is mainly used as an oil painting medium and in tempera emulsions. Linseed oil gives a smooth effect to paint but it tends to yellow with age. As the Old Masters relied on a heavy layering of the paint surface, Linseed oil was the best medium because of its fast drying time.
M
Madder lake This purplish color is derived from the root of the madder plant and is impermanent. Alizarin madder lake is an artificial pigment and it is more permanent than natural madder lake.
Mannerism The artists of the Mannerist period (c.1520-1600) flouted the traditional ‘rules’ of classical and Renaissance art. The chief characteristics of the style are vivid and unnatural colors and elongated and exaggerated figures. Mannerism was supplanted by the Baroque period.
Mastic resin The best type comes from the pistachio tree. Mastic resin is used for making varnish and it prevents wrinkling, shrinkage and decay. It also gives depth and clarity to colors.
Medium Specifically. the liquid used to bind pigments to make paint. The term has also come to mean a type of paint. Oils. tempera and water, for example, can all be described as painting media.
Megilp A drying oil which gives colors a buttery consistency.
N
Naples yellow A color which was popular with the Old Masters. Naples yellow is heavy and dense and so it has excellent covering properties. It is compatible with all other colors, unaffected by light and rarely cracks.
Neoclassicism A movement which began in Rome in the mid-eighteenth century as a reaction against the Baroque and Rococo periods. The aim of the Neoclassicists was to recapture the splendor of Greece and Rome . The artists made a conscious effort to duplicate the antique both in style and subject.
O
Ochres Yellowish earth colors which tend to be impure. These pigments have a fairly good covering power and drying capacity and they are very permanent when pure.
Orpiment yellow A brilliant, poisonous yellow used by the Old Masters. Cadmium yellow has come to replace this pigment.
P
Palette This refers to both the surface on which the artist lays out paints and also the colors which are used.
Panel A painting term for a rigid support such as wood. If wooden panels are used, they must first be sized to prevent the paint from being absorbed.
Pentimento Derived from the Italian meaning ‘repentance’, pentimenti are the changes in composition which a painter makes while producing an oil painting. These alterations are visible in infra-red photographs and are sometimes useful in determining forgeries.
Picture plane The region of the oil painting which lies directly behind the frame and separates the viewer’s world from that of the picture.
Pigment Any substance which when mixed with a liquid, creates a color which can be used for painting. Pigments are generally organic (earth colors) or inorganic (minerals and chemicals).
Pointillism An oil painting technique developed by Georges Seurat out of the Impressionist theory of color. Dots or blobs of color were placed beside one another to create an ‘optical mixture’ in the viewer’s eve. If a blue dot was placed beside a yellow one, it was said to create a more brilliant and intense green than if the two colors had been mixed on a palette.
Pop art The dominant form of art in England and America in the late 1950s and early 1960s: the term is derived from the word ‘popular’. Pop artists, such as Roy Lichtenstein, used material from comic-strips, advertising and films. The movement has been considered a direct challenge to Abstract Expressionism which preceded it.