Minecraft wiki entry for Chalkboard, associated text: Chalkboards may be placed on the top or side of other blocks (including non-solid blocks like fences, glass, rails, and other chalkboards). To place a chalkboard, use a chalkboard item while pointing at the block the chalkboard should be attached to. To place a chalkboard on a block that can be interacted with by the use control (for example, chests, note blocks, etc.), sneak while placing the chalkboard.