You can use any yarn and appropriate hook, but I suggest standard DK acrylic as it’s meant to be a simple, cheap, heard-wearing item. This project is worked entirely in one go with only thread ends and the button to sew (plus any decorations), so it’s great if you can’t have scissors on you for some reason.

More pics & write-up at http://www.crafts.carolinewood.co.uk/2011/02/happy-valent...