I knew from the start that I wanted to frame and hang them, but I had a little trouble because the cards were a bit 3D and I quickly realized that they weren't sized to any standard North American frame.
They're actually a really neat idea: just pile as many mini frames behind/in front of the piece of art as you like and get the depth you need.
I mounted each card on burlap printed scrapbooking paper trimmed to fit.
Right now the pictures are hanging in our 1970s rec room, ready to be the inspiration for a modern makeover to that floor of the house. I'm so very pleased with their cuteness and originality.