Sent to you by nunok via Google Reader:
To make a few quick and colorful placemats—that will be perfect to spice up your table for any occasion—we gathered a few supplies from the local craft store: poster board, spray paint, tape, paper doilies, and scissors.
Lightly tape the paper doilies on the poster board. We used two different sizes and placed them randomly so that all the placemats would be a little bit different. Once everything is in place, you can start spray painting—make sure you are in an open space and the wind isn't blowing! To get the uneven coverage, spray lightly and do a few layers. Since perfection is not the goal, you really can't do this wrong!
The sun dries the paint quickly so you can pull the doilies off soon after spraying them. Be careful if they are still a little wet.
Step back and admire your handiwork! Next step is just cutting the painted poster board into four placemats. We folded the board in half and then in half again and followed the lines to cut—did we mention it doesn't have to be perfect?
Now just add a tasty treat to the table and you are all set! We even used a leftover painted doily for a little added décor.