Jamie told me that she would love to have some chalkboard speech bubbles for the photo booth at her wedding. I had a lot of scrap luan laying around the garage, and we had temps around 50 one day recently, so I got to work.
Scrap plywood pieces
The curve of a can rounds speech bubble corners
Use a Dremel or Jigsaw
Sand rough edges
Paint speech bubbles with chalkboard paint
Add handles to back of chalkboard speech bubbles