My cousin, Sue, found this 36"x48"canvas in a dumpster.  It was covered in oil cloth (?) that had a painting on it.  We stripped the oil cloth off and I gave the canvas a few coats of gesso.  The rescued support is now "Rainbow Fog".  Thank you, Sue!  Nothing like a free canvas to get the paint flowing.  The best times to get inexpensive large canvases is when the CU art students leave.  They ditch the paintings they can't ship or carry at the thrift stores.