The letters were cut out on my Cricut machine, using the "Stamped" cartridge. If I haven't mentioned it before, I have a love affair with my Cricut machine. It is seriously the best invention to hit crafting since, well, EVER. I use my machine all the time, and if you don't have one, you are missing out. (I should be a spokesperson for these for real!) You can find deals on the more basic machines for under $100. I have the Expression, which cuts bigger shapes and letters (up to 23" high), and it is awesome. I scored it on Black Friday a few years ago for $200. Put it on your birthday wish list immediately, or just treat yourself for no reason. You deserve it!
A close-up of some detail
My little man