Art Terms


A Acrylic paint : A type of paint made using a synthetic resin as the medium which binds the pigment. It has the advantage of drying within minutes and is also water soluble.

Aerial perspective : This is the optical effect caused by light rays refracting in the atmosphere on objects. The further away the object the cooler and lighter it becomes, e.g., the green mountain you are standing on becomes bluer (blue-green) and lighter in colour as it recedes into the distance until the very distant section of the mountain becomes a blue-purple until it becomes a faint purple in the far distance.  If this is reduced to a panchromatic or monochromatic (black and white) painting the closer mountain (dark shade) would gradually become lighter and lighter in shade as it disappears into the distance.

Alla prima painting : This means that a painting is painted in one session or sitting, wet-in- wet, without first putting down an under-painting. Here one begins with a blank white board and immediately starts the painting with colours directly onto the board, non-stop, until the painting is completely finished. This is also called "direct painting" or "one-layer painting".

Atmospheric perspective : See Aerial perspective above.

 B Bloom : This is a whitish colour or "clouding" that may form when moisture is allowed to contaminate the varnish while it is drying on a painting.

 C Chalking : This occurs when ultra-violet rays attack the surface of the paint which eventually becomes dull and starts flaking. The resulting powder form is called "chalking".

Chiaroscuro : A technique where one uses dramatic contrasting of colours in an exaggerated tonal range. In other words there is a dramatic contrast between light and shade. It also means the skilful use of light and dark and the in-between shadings to produce realistic 3- dimensional effects on a 2-dimensional (flat) surface.

Chroma colours : Normally the pure uncontaminated colour straight from the tube. This does not include black or white as these are not colours at all. White occurs when ALL the colours are reflected away of a surface, and black occurs when ALL the colours are absorbed by the particular surface.

Complementary colour : The colour opposite the selected colour on the colour wheel is called the complimentary colour, e.g., if the colour Red is selected, then the opposite colour on the colour wheel is Green, which is called the complementary of Red. The complementary of any primary colour is the mixture of the other two remaining primaries.

Cool colours : Blues, greens, and purples are considered cool colours. See also Warm Colours.

Cracking : Also called "crackle" or "craquelure". Cracking in an oil painting usually occurs when the top layer of paint dries quicker than the layer underneath. As the under layer dries it shrinks slightly, with the resulting cracking of the top inflexible harder layer. Cracking can also occur if a canvas painting is incorrectly rolled up. Canvasses should ALWAYS be rolled up with the painted surface to the OUTSIDE of the roll. Should cracking occur, the cracks are "closed up" when the painting is unrolled and not so noticeable. A Painting should never be kept rolled for any length of time as this is a sure way of causing cracking. (See Fat over lean).

D Dry-brush technique : This is a "broken" colour effect produced by stroking a semi-dry or rather stiff colour on a brush lightly over the surface of the painting. This effect is heightened by the roughness of the support surface. What actually happens is that the paint is placed or rubbed off onto the humps of the roughened surface and this causes the broken colour effect.

 E Easel : From the Dutch word "esel" meaning "donkey". A donkey is mostly used for carrying loads therefore the easel (anglicized form of esel) is used to carry the support or canvas board or stretched canvas. The easel can be anything from a table model to the very large studio type models. Others, like the French box easel, are modified to be able to carry all or most of the artist's materials when painting outdoors.

Encaustic painting : A painting where a special technique using wax is used. This techniques involves pigment mixed into hot wax which is then applied to the painting surface.

 F Fat over lean : Often one reads about the fat-over-lean rule. Here it means that the original layer on the painting surface is applied as a thin layer, blocking in the basic underpainting colours. These colours are not necessarily the final colours. Each layer of paint that is subsequently applied over the other should have slightly more oil in the medium than the previous layer. This ensures that each previous layer dries quicker than the one before it. In other words each layer added is more flexible that the previous layers. This is of vital importance if one paints in different sessions over a period of time. This method will eliminate the possibility of the top layers cracking over a period of time. (See Cracking)

Ferrule : This the small section of tubular metal that hold the hairs of the paintbrush onto the wooden or plastic handle.

Fixative : Originally this used to be a lacquer liquid that was physically blown over a pencil or pastel drawing in order to prevent smudging. Nowadays fixative comes in an aerosol can that applies a very thin layer of special non-acidic non-yellowing plastic mixture onto the drawing surface. Resist the temptation to used hair spray instead of artist's fixative over your drawings if you value your drawings. Over a period of time (sometime s, years) it will cause yellowing of the paper. I have experience of this. In my case it took about 15 years for the yellowing to show up and spoil my drawing!

Fugitive colours : Fugitive in this case means the opposite of permanent. Some colour tubes are marked with a number of stars to indicate the degree of permanence, or lightfastness, of the paint. The more the number of stars the longer the particular colour will last before fading occurs. Where only one or two stars are indicated it means that these particular colours will eventually fade, and, under certain adverse conditions, fade away completely,

G Gesso : This is an Italian word which means a chalky substance. Gesso is a mixture of the chalky substance with glue to size (seal) a surface prior to applying the paint. Often Gesso is mixed with rabbitskin glue and the mixture applied to the painting surface. Today there are quality acrylic Gessos which can be used instead of the traditional Gesso.

Glaze : This is a special layer of very thinned down colour (normally slightly darker than the colour beneath it) that is applied transparently over the dried paint layer beneath it. Many of the Old Masters used this method to build up, layer after layer, until the final painting. This method usually resulted in a very luminous type of painting. (See scumbling)

Gouache : This is an opaque (solid, non-transparent) colour. It is water-based and can be worked into and blended similar to oil painting. Even after the painting has completely dried it possible to come back and blend other colours into it. Here one can apply lighter colours over the darker colours, which is not possible with the normal transparent watercolous.

Granulation : This normally occurs in watercolour painting. It is the term used when the coarse granules of the pigment in certain colours settle out after the water has dried. The beautiful effect of granulation is better seen, and used, in the coarser surfaced watercolour papers.

Grisaille : (Pronounced Gri-ZAY) This comes from an French word "gris" meaning "grey". A grisaille drawing or painting is where a monochromatic (single colour, usually grey - some artists use raw umber or a purple colour) painting is made in various tones of grey or a neutral colour - from dark to light, similar to a black and white photograph. It is possible to produce beautiful paintings by applying different glazes over this dry grisaille painting. It is method I regularly use when painting animal studies and still lifes. It is not a new method. The Old Masters developed it and most of their famous paintings were produced by using this method.

Ground : This is the layer on which the paint pigment is applied. It can be Gesso, acrylic, glue covering, etc. It is not the support, but rather the preliminary layer applied to the support in order to seal the support surface and to provide a "grip" for the applied colour.

 H Highlight : This is the lightest tone (usually white or the very lightest tone of a particular colour) in a painting. The highlight usually occurs on the edge or on the rounding of an object and on the side that the light source originates from.

HP (Hot Pressed) : This is normally applied to artist's quality watercolour paper where the paper is pressed under heat to produce a very smooth surface.

Hue : Usually used to indicate that substitute materials or pigments are, or have been, used instead of toxic substances or heavy metals to produce a certain colour. If you have an old paint tube in your possession with, say, Cadmium Red, this most likely contains pure cadmium pigment which is a toxic or dangerous substance. Today most tubes will now state: Cadmium Red Hue. This means that materials, other than the toxic cadmium, are used to produce a colour close to the original Cadmium Red.

 I Impasto : From the Italian word "pasta" or paste. This is the technique of applying (pasting) a thick layer of paint onto the support. The paint is usually applied with a painting knife or a bristle (hard) brush in such a manner that the paint stands in heaps or ridges. This creates a very heavy textured surface in a semi three-dimensional form. An exciting aspect of impasto painting is that each heap or ridge of paint creates its own automatic highlight and shadow, which changes as the outside light source reaching the painting changes in position.

Impressionism : A method of painting so as to give the general effect without any detailed painting. Objects and scenes are rendered without attention to details in an almost sketchy or hasty way.

Imprimatura : The preposition "im" means "not" as in "improper"; "prima" means the primary or the "main" part of an object. Therefore, an imprimatura painting is NOT the final painting, but rather the first thin transparent colour laid over the white support prior to beginning the "prima" or the main and final painting. This imprimatura painting is useful for those who cannot paint directly onto a white support. It also helps to bring the parts together into a whole.

Infra-red : This is the colour, in the colour spectrum, beyond the red end of the spectrum where the red becomes so dark that it becomes "black" to the human eye. See also "ultra- violet".

Inorganic : Inorganic material means material that is not living, such a minerals, stone, sand, etc. Mineral turpentine is a liquid that is obtained from compounds other than living compounds. See "organic".

Intensity : The intensity of a colour is simply the strength of that colour. To made a colour more intense, more pigment is added to that colour. Normally student's colours have very much less pigment than the artist's quality paints - that's why it is cheaper. That is the reason why I personally don't recommend student quality paints for paintings you want to last for a long time, or for a painting you would normally paint for the commercial market, or, in other words, paintings you sell.

 K Key : One often hears of a painting being either a "high key" painting or a "low key" painting. A "high key" painting is one which most of the colours and tones are bright and lively. The "low key" painting, on the other hand, is one that is normally dark and sombre with very few bright areas and/or highlights.

 L Lightfastness : This a term which indicates how the paint reacts to light and UV attack. See also "fugitive colours".

Lignin : This a naturally occurring substance in wood, which on its own is acidic in nature. If this is not extracted during the paper-making process it will eventually cause the paper to yellow with age. It is still present in the cheaper grade wood-pulp paper. Not all artist's paper is free from lignin however. Check the paper you buy and make sure that the package indicates that the paper is acid-free.

Local colour : This is the basic overall colour of an object when viewed in natural (even, diffused) light. The object may take on a different colour in other types of lighting, e.g., if the object is yellow in natural light, it will take on an orange hue in a room with an ordinary incandescent light bulb, and look very blue with some fluorescent tubes.

Luminism : "A polished and meticulous Realism in which there is no sign of brushwork and no trace of Impressionism, the atmospheric effects being achieved by infinitely careful gradations of tone, by the most exact study of the relative clarity of near and far objects, and by a precise rendering of the variations in texture and color produced by direct or reflected rays" [American Luminism," Perspectives USA, Autumn 1954]

M Mahlstick : The word "mahl" is a German word meaning "paint". So a mahlstick is actually a painting stick. It normally a long heavy dowel with a soft ball or cloth pad at one end. The ball is placed on one end of the painting as a support and the dowel is used to support and steady the brush hand while painting over the wet surface.

Masking / Masking fluid : Masking fluid is a rubber solution which has been coloured a light yellow to make it easily seen on the white paper. It is applied to the paper in order to preserve highlights in watercolour paintings. It can also be applied over an already applied colour in order to preserve that particular portion of the painting.

Masking out : This is similar in principle to the masking fluid except that masking tape, magic mending tape or low-tack stencil paper ( as used for air brush work) is used. The tape is gently and carefully trimmed to suit with a very sharp craft knife.

Medium : A liquid used to thin down the oil paint without adversely affecting the properties of the oil paint itself. Each manufacturer has his own special formula but all should not stop the pigment from binding Some mediums are slow-drying while others are quite quick-drying so each artist will have to try out which one suits their own style of painting as well as special requirements. "Mediums are traditionally used in oil paintings as a liquid diluent to extend the color and add greater fluidity to the paint as it comes from the tube - without compromising the chroma."American Artist, Technical Page, Aug 1999

Modelling : For the artist this means the use of shading, in which the illusion of a three- dimensional subject is rendered on a two-dimensional flat surface.

Monochromatic painting : This a painting which is painted using a single colour and includes all the necessary range of tones. A black and white photograph is a good example of what a monochromatic painting should look like. A monochromatic painting is most often used as an under-painting prior to the final over-painting in full body colour. It is also used as the preliminary in which the final painting is made up in stages by a series of colour glazes that allow the under-painting details to show through in the final painting. (See grisaille)

N Not (not hot pressed/cold pressed) : Hot pressed paper is a smooth surfaced paper. The "Not" paper is all paper that has a textured surface; all surfaces between the smooth to the very rough.

 O Oil Paint : Oil paints are made from highly ground pigments suspended in a drying, or semi- drying oil such as linseed, poppy or safflower oil. These oils act as a binder for the pigments.

Opaque painting : As opposed to transparent painting, opaque painting used paint with white added to provide "body" or covering power. Transparent colours allow the under-painting to show or shine through, while opaque colours cover the under-painting completely.

Organic : The opposite to inorganic. Organic compounds came from living organisms such as plants, etc.

Oxidation : Occurs when oxygen reacts with a substance. One example is rust on steel. Another example is the browning that occurs just after an apple is cut in half.

P Palette : A wooden board on which paint is mixed. It also may be from glass, a tile or plastic. The palette may just lay flat on the table or may have a thumb hole in it so that it may be held in the hand for portable usage. A palette is also the range of colours the artist chooses for the painting in hand.

Pastel : Pastels can be either in stick form or in pencil form. The pigments are bound in a weak binder in order for the pigment to detach from the stick in a powder form when rubbed across a coarse surface. A slightly stronger binder is used for the hard pastels.

Perspective : The art of drawing so as to give effect of solidarity and relative position and size (The Little Oxford Dictionary). Check with Leonardo books

Pigment : The substance that gives the paint it's distinctive colour. This can be sand, plants, charcoal etc. The substance is finely ground and added to a medium to make it fluid.

Primary colours : For solids, such as for paints = Red, yellow and blue. For printing = Magenta (red), yellow and cyan (blue). Fir light = Red-orange, green and blue-violet (such as in a rainbow).

Primer : Is a substance that is applied to a surface in order to provide a suitable prepared surface for painting or drawing on. The primer should provide a surface with "bite" or "tooth" on which the paint can grip on. The primer should also provide an impervious seal between he support and the paint. The primer for oil painting is usually an acrylic paint.

R Realism : Any art work in which the objects are rendered as close to the natural as possible and with all the necessary detail. The work is rendered almost photographically.

Resist : Where a particular area in a painting is to be kept clear from another colour a resist is used. This is a protective substance, such as masking fluid, candle wax, adhesive tape, etc. which is applied to the painting surface.

Rough : A term usually used in watercolour painting to describe a very rough surfaced or rough textured paper.

 S Saturation : A colour that has reached it's full intensity. During the heat of the day most colours are washed out (blue part of the spectrum) and they gradually increase in saturation and intensity as the afternoon moves on through to late afternoon. ( blue to orange to red spectrum). Similarly saturation decreases from very early morning to noon.

Scumbling : A technique where an opaque, or semi-opaque colour (usually a lighter colour than the under-painting) is thinly or loosely brushed over an under-painted area so that the painted area beneath it shows through. (See glaze.)

Secondary colours : The colour opposite the selected colour on a colour wheel, eg., If the selected colour is red, then it's secondary colour is green (the opposite colour). Conversely, red is the secondary colour of green.

S'graffito : A technique where, in the various materials, the top layer is scratched in order for the underlying colour is revealed

Shade : A shade colour is any colour that has been mixed with black. Be careful when mixing black into your colours. It is nor called the colour of mourning for nothing! If not used properly it can, and will, kill any painting! We teach our student to obtain the same results without the used of black. If you ever need black for whatever reason, it is best to mix it using raw umber and French ultramarine blue. There are other colour combinations that produce the same result and give a black that is not "dead".

Size : Size is a substance, such as glue or gelatine, that is applied to the painting support to provide a surface that is less absorbent than the original paper surface. Normally this is applied prior to applying the primer layer on raw canvas.

Solvent : A solvent is a liquid that will dissolve a solid substance into liquid form with itself. The normal solvent for oil paints is the organic type of turpentine which is obtained from pine trees. Do NOT thin your oil paints with mineral turpentine except for the thin under-painting washes. Use mineral turpentine only for cleaning you oill painting brushes. Remove ALL excess mineral turpentine from your brush with a rag before using it again.

Spattering or splattering : The technique of flicking paint off a stiff brush or toothbrush onto the painting surface to create a mass of irregular spots of paint. Spray guns and airbrushes are able to create the same effect with special nozzles.

Squaring up (grid method) : A technique where a grid of squares is superimposed over an original drawing, photograph, etc., in order to either enlarge or reduce it by transferring the contours or edging of the subject(s), square by square, to another painting surface that has been prepared with squares to suit the size of the new drawing.

Stump : Usually a tightly rolled piece of paper, or similar material, which is used to smooth the shading of a pencil, charcoal or pastel drawing. (See tortillon)

Support : The canvas, canvas board, stretched canvas, wood, paper, etc., on which the painting is made.

T Tackiness : This occurs when the paint is not yet completely dried out. In this state it is often used to "pull" the paint off a brush or painting knife for special effects.

Tint : A colour that has been mixed with white. This creates a lighter colour of various grades of the parent colour.

Tone : A tone is the degree of darkness or lightness of a colour. When a colour is tinted with white to form a range of tints from the parent colour to almost white, this range is called the tonal range of that colour.

Toned surface : This is a surface that has been given a preliminary colour other than white. Many artists tone their painting surface prior to beginning their painting as they find the stark white very intimidating. If one paints en plein air (outdoor painting) then it is almost a must in order to reduce the glare off the canvas or paper to the absolute minimum.

Tooth : This is the grip provided (by the slightly roughened surface) for the adhesion of the paints onto the surface of the support.

Tortillon : See Stump

Transparent painting : This is the basis of watercolour painting. In purist watercolour painting no white is used. Reliance is placed on the white of the paper, and transparentness of the paints (less water and more pigment reduces the white of the paper, while more water and less pigment allows more of the white paper to shine through).

Trompe l'oeil : A term for the type of illusionistic painting or technique where the viewer is tricked into thinking that the painted objects are real.

 U Ultra-violet : The colour or wavelength beyond the violet end of the spectrum.

Under-painting : The initial colour wash or monochromatic painting over which the final layer(s) of paint colours are placed.

V Value : The relationship between the lightness and darkness of a colour or colours.

Varnish : A protective covering or translucent resinous or other layer which is brushed or sprayed over the surface of the painting.

Vehicle : The medium or the binder in which the pigment is held together in. In other words it is the carrier for the pigment.

W Warm colours : Reds, oranges, and yellows are considered warm colours. See also Cool Colours. Wash : This the term for the thin or transparent layer of paint applied to the painting surface. This is mostly used in watercolour painting.

Watercolour : A method of painting where the pigments are mixed with a gum, such a gum arabic, etc., and which is then diluted with water in order for it to be applied to the paper.

Wet-in-wet, Wet-into-wet : This is the method where paint is applied to an already wet under-painting, as opposed to a wet paint over a dry surface. In Watercolour painting this method gives exciting and mostly unpredictable results.

Wetting agent : Water or any other liquid which aids the application of colour to the painting surface. This is often used to provide an even coverage of colour.