Traditional methods of hanging posters, such as tape, glue or staples, can damage walls. A safer alternative is poster putty, which can be made at home for a fraction of the store price. It can be removed easily without causing damage.
Place 1 tbsp. glue and 1 tbsp. water into a shallow bowl. Stir until the ingredients are well incorporated.
Pour 1 cup water and 1 tbsp. borax into another small bowl. Stir them.
Add 1 tbsp. of the borax water to the bowl that contains the watered-down glue. Stir the ingredients until they begin to form a putty, which can take several minutes. Add an additional tablespoon of the borax mixture for a more solid consistency.
Place the putty into a zippered plastic bag to ensure it does not dry out. Remove small amounts of the putty, work them into balls and place them onto the walls to hold up posters.