On Fri, 12 Feb 2010 04:58:44 -0800 (PST), Andy Dingley
wrote:

There's no glue, sealing
or framing involved, just half-a-dozen metal screw clamps around the
edge, which were also used for their suspension wires.

Cheapo DIY version ist use small binder clips. Also availabe in silver...

http://commons.wikimedia.org/wiki/File:Three_binder_clips.jpg


Thomas Prufer