Dear Clive,
If you try the "search messages" function at the top of the Forum pages, you can see what has already been written...and the "Preparing Canvas" thread is a terrific resource:
http://forum.portraitartist.com/sear...der=descending
I like a rigid surface, and use 1/4" Masonite, and Demco archival bookbinder's glue to adhere my pre-primed linen. I learned this technique from Dan Gerhartz, and if it's good enough for Dan, it is certainly good enough for me.
http://www.demco.com