Digital BW, The Print

I've recently started mounting my digital prints (printed on 
Hahnemuhle 308 Photo Rag) using conservation mountboard for the mat 
and foam core board for the backing.

I have heard T-hinges mentioned as the best way of mounting prints, 
but can't find any specific details of how they work.

Could anybody point me to a link on the web which shows how they 
work?

Thanks.

Peter