Glossary of Art Terms: O

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offset-lithography

The printing process in which an inked image on a metal or stone plate is transferred to a smooth rubber cylinder and then to the paper. A halftone pattern is used for each color and each of these is offset slightly in order to produce all the colors and tones required for the image. Offset-lithography is used extensively by the publishing industry but is also used to produce fine art prints.

oil paint

Paint consisting of pigments ground into oil, traditionally cold-pressed linseed oil. The resulting thick and buttery consistency is prized by many artists and provides unique characteristics in handling and techniques.Oil paints oxidize into a tough leathery film, and remain remarkably stable over time. However since oil paintings do begin as organic material, subject to decay, some precautions should be taken in caring for them.

oil painting

Artwork created using oil paints as the medium. Originally oil paintings were produced on rigid panels following the customary procedures of fresco and tempera painting. Though he wasn't the first to combine pigments with linseed oil, Jan van Eyck, during the 15th century, developed recipes and a new technique involving various mineral pigments, calcined bones and ground glass. The remarkable works he produced began an new era in fine art painting.

The techniques of oil painting were further developed by Antonello da Messina (who introduced lead oxide to oils), Leonardo da Vinci, Rubens and many others.

oil portrait

A work of art done in the medium of oil paint, depicting a person's likeness. See portraitOil portraits have been the choice for traditional formal portraits for centuries.

You can find some fine portrait artists here.

Op Art

A modern art movement and style in which artists created very effective images having the novelty of optical illusions as the main focus of the artwork.

open edition

A set of multiple fine art prints where the number of prints to be produced is unlimited. If the number if prints is predetermined and limited, the edition is then preferred to as a limited edition.

original

The term 'original' can imply exclusivity or the idea that the work is 'one of a kind' rather than a copy by any method including offset-lithography, digital printing or by forgery, or copies for study purposes. Not all hand-painted works can be considered original since the term also refers to the image being newly created, so a painted copy of another work is not an original.

The term may also apply to a reproduced series, as in 'original serigraph', which refers to the edition as original, since the image was conceived as a serigraph print and the product is the set of prints. Then, any subsequent copies would not be considered original, as is the initial series.

overpainting

A finishing layer of paint applied over either the base layer of paint or subsequent layers, once it has dried. See underpainting.