Definition & Meaning of "stretcher bar"in English

What is a "stretcher bar"?

A stretcher bar is a type of wooden or metal bar used to stretch and support canvases for painting. It is part of a frame that holds the canvas tightly in place. The stretcher bar is attached to the edges of the canvas, and the canvas is pulled over it and secured to create a smooth, tight surface. This ensures that the canvas remains stable and even during painting, preventing it from becoming loose or wrinkled. Stretcher bars are commonly used by artists to prepare canvases for artwork.