The Small Markerboard A Frame acts as the perfect alternative for standard chalk-based sidewalk signs. Use this portable marker board with our liquid chalk markers and you’ll have a bright, brilliant display that no customer can ignore. The writable area on these a frame signs is 17.5"W x 27.5"H and the frame is made durable wood and consists of an attractive mahogany finish. This a frame sign board is only for liquid chalk or neon fluorescent markers; you may not use regular chalk on it.