canvas vs. canvass

A canvas is most often a tough, heavy cloth made from cotton, hemp, or linen, used especially to create sails, tents, or a surface on which to paint. In the case of paintings, canvas is the word for the surface itself, not just the materials from which it is made. (By extension, it can also refer figuratively to a background against which an event unfolds, as in, “The French Revolution began against a dark canvas of poverty and oppression.”)

The similar word, canvass, has very different meanings. It is most often used as a verb meaning “to solicit votes, orders, advertising, or opinions (from people)” or “to investigate, examine, discuss, or scrutinize (something) closely or thoroughly.” For example:

Because canvass has such specific uses, and because it is very often used in the conjugated forms canvassed or canvassing, the common mistake many writers make is to use canvas instead when the verb is in its base form. Just be aware that the word must end “-ss” if you are using it as a verb; if you are describing a physical object, it is spelled with just one “-s.”