Stretched Canvas 20cm square. Good quality stretched, primed, unbleached cotton canvas - stapled on the reverse of stretcher 280g Dimensions:- 20 x 20 cm [8 inches square], depth 1,6 cm Sold as a PACK of 10 Canvases [pack cannot be split]. The canvases are supplied with a bag of tightening keys or wedges, used if the canvas begins to sag a little on the stretcher. You put them into the slots made for them in the corners of the stretcher bars, then tap them in further to tighten or square up (align) the canvas.