I have seen Dr. Mark's prints on the walls at the old Elevator lab, and they are awasome.
I hope to find the time to get down to see this show.
There is also a NFB documentary film on Mark's work. If you live in Canada you should be able to get it through your library. It has aired on TVO a couple of times, and I have enjoyed viewing it as well. In it you can even catch glimpese of out Bob Carne in the orange jump suit flipping prints.