What is the difference between a ‘stretched’ and an ‘unstretched canvas’?
Stretched canvas is canvas that has been stretched over a wood frame ready for display. If you look on the back of the painting and see wooden bars (stretcher bars), then you have a stretched canvas! A stretched canvas can be displayed without a frame, but sometimes adding a frame can really enhance the piece too.
If you purchase a painting that is on unstretched canvas, it will require some extra work before it is ready for display. The best option is to take the painting to a professional framer and ask them to either stretch it onto bars, or mount it onto a panel. Mounting it onto a panel will involve glueing the back of the painting onto a hard surface so that it can then be framed.
Mounting a painting is usually the less expensive option, compared to having it stretched, but will require purchasing a frame. With a painted on stretched canvas, it can be hung without a frame. You win some you lose some