I usually use standard stretched canvas but was introduced to these wonderful structures when creating my piece for the Kent Street Project.
LOVE, LOVE, LOVE them, especially when you need strong support so you can drill or screw into them.
The photo on this piece is an actual toner transfer done with a toner copy, gel medium and a bucket 'o elbow grease. The photo is a picture of a class at Pierce school in 1905 (the school was already 50 years old by this time!)
The book on the bottom is a front cover from a primary reader circa about the same time and the other images are from the inside pages of this book and a national speller book. I love the illustration on the right hand side, it's hard to make out here but it's a teacher at a black board and the first thing she's written is a is for ale. LOVE it!
If you're at the auction, bid early, bid often and bid loudly!