Canvas is sold at so much the square foot; that which is twilled, or ticking as it is otherwise called, costing fifty per-cent more than the plain. It is kept, ready-primed, in rolls of various width, at the colormen's, who need but a few hours notice to cut it and distend it on the frame to any proportion that may be desired. There are however certain sizes which have obtained for many years among artists, especially for portrait-painting, and these are always kept on hand at the shops, ready-mounted on the frames, or stretchers’,,