Cut out two panels of sturdy 1/2-inch plywood or other form of lumber. A standard width for many signs is 24 inches wide with a height of 36 inches.
Prime both sides of each panel with an exterior oil-based wood primer, similar to the final color of your sign, with a 2- to 3-inch paintbrush. Allow the wood to dry for the recommended time on the paint can.
Paint the same two panels with an exterior oil-base paint, still using the 2- to 3-inch paintbrush, working with the grain of the wood. Cover again with another coat if necessary after drying between coats. Dry thoroughly.
Position two butt hinges between the two panels, with the top of the hinge extending just past the top of the wood panels. Mark their placement with a pencil. Screw one side of the hinges into the inside of the top panel and the second side into the bottom panel using an electric drill. Repeat for the second hinge.
Add the wording to your sign and set up by opening the panels at the bottom and standing up the sign.