DIY Address Plaque & Planter Box Once we had everything cut and ready to go, I painted all the wood. Since this was going to be outside, I used KILZ primer to ensure a lasting finish. Then painted all the wood in black. Then of course a coat of polyurethane to seal it. Now time to put the address numbers on. We found our house numbers at The Home Depot. They can be used two different ways, flat or floating. We decided to have them lay flat on the wood.