I didn't spend a dime on this project. I already had all the materials and since it was the first project and I was super afraid of screwing it up in some way I used unlikely materials. Mostly, you see these signs on a piece of wood that's been painted. I got a little more creative (or cheap whichever you prefer).
piece of cardboard. This was actually a flap off of a diaper box.
Black construction paper
Mod Podge-the greatest stuff ever!
All I did was apply my vinyl to the construction paper. Then, cut the construction paper to fit the cardboard. Coated the cardboard with mod podge and applied the construction paper. Then, I coated the top with 2 coats of mod podge. I used a Philips head screwdriver to punch holes in it and then added the ribbon hanger. And there you have a cheap Naptime warning sign. I am going to add a sign to the back of it about removing your shoes upon entering. That way I make use of both sides.
The real kicker of this project is this is the second day that I've hung the sign at naptime and someone had the nerve to ring my doorbell! My husband of course told me that he knew this would happen and found it to be quite funny. I wasn't amused due to the fact that I was dead asleep because I worked until 3am. Plus it of course woke up my son and then naptime was over. I wanted to cry.
Moral of the story: Please call before showing up on someone's doorstep or at least read their signs.