Following a lead from Tash, and looking at an excellent example of this craft, I have done some research on this area and found some interesting sites. I have to confess that pop up is something I have really only ever associated with Children's books over the years, and I bought one or two as presents. Last night I had a look a a couple of sites, from which a couple of screen grabs are posted.
Link to a good site: http://robertsabuda.com/snpk1102a.html
