Hi Clare, the website from the Envelopeners producers it's this one: http://inventrade.com/engels/welkom.htm They are really a great tool.The price for large orders directly by them (100 pieces or more) it's really convenient.
This little origami cutters can be also found in many other origami online shops and associations, for example in the website from Julia Schönhuber ( http://www.papierdesign.at/origami-shop), that I also reccomend for the wonderful origami paper she have :-) Cheers and good folding everybody! Coral PS
