Buy Accutane
-
Thermo-chromic Ink, this has been a real favourite over the years, always really effective and gets loads of great feed back, this really does engage the recipient. I think this is best left to your imagination, the only thing to add is the ink is very matt and we have learnt to always use a barrier over this ink, a laminate or a spot UV varnish! this will prevent any unsightly scuff marks.
