Learn About the Dimensions of Artwork
In English, one word may have various meanings. It is the same in the field of fine arts. In the fine arts, size has two meanings: dimensions, and pre-primed canvas surface.
Size as Dimensions
An artwork's size is measured by height, width and/or depth. Paintings are measured by height first, followed by width. Sculptures and three-dimensional installations are measured by height, width, and depth. Measurements of artwork are typically done by the centimeter (used in Europe and Asia) or by the inch (used in the US).
Recording the accurate size by experts such as archivists, registrars, or appraisers is necessary for filling in documents such as condition reports which are required for auctions, transport of exhibitions, acquisitions, and insurance or tax appraising. In some cases, the size of an artwork will be recorded in both centimeters and inches. When keeping digital database records of artworks, the size of the piece is always included.
Sizing in Oil Painting
Size is a substance put onto the surface of a canvas to prime it for painting. Oil paints cannot touch the fiber of the canvas, or the canvas will erode and disintegrate.
Oil painters always apply a sizing to the canvas first. Traditionally, painters use rabbit-skin glue as a size to fill in the pores of the canvas, before they add the white primer or gesso layer. The size will tighten up any slackness of the stretched canvas, providing a smooth, taut, and uniform surface on which to add the primer.
In the field of painting conservation, the conservator works from the back of the canvas, repairing or replacing the linen strands which are adhered to the sizing.
The Artist's Handbook of Materials and Techniques by Ralph Mayer is the definitive reference book for oil painters who wish to learn the exact formulas and mixtures for grounds, mediums, and pigments, and the chemistry of such artistic materials.