In the detailed instruction is said that you can use any 3D medium and because I have already presented hot glue ideas for similar things I have called the card hot glue card :)
Links:
Hot Glue Card (Tutorial for my 3D technique) (photo tutorial)
More precise explanation about the making and the medium in the blog entry ‘3D-effect painting tutorial’, scroll down to ‘Note on supplies’.
Here at unikatissima:
Entries containing the word ‘hot glue’