Wet canvas handle

Handle to hook under the frame of canvases to facilitate carrying when they are wet; my mother paints and wanted an easy way to help carry the canvas back to the car with everything else.

Width at the bottom was designed as 18 mm and comes out on my printer at about 17.75 mm, so please measure the canvases you tend to use, because I found widths to vary greatly - this fit only two out of the three canvases I tested it with afterwards. May redesign in the future to support different widths...