Curb Signs and A Frame Signs Wide selection of Sandwich, Sidewalk, Markerboard signs. Signs Direct is your best source for outdoor signs and stands..These sidewalk poster stands feature snap open spring Sidewalk sign holders with a magnetic customers know right off the bat what’s for sale..Shop for a frame signs or an a frame sidewalk sign at WebstaurantStore, we have a large selection of a frame sign boards for sale at the lowest prices. .Sidewalk signs are a great form of outdoor advertising for small businesses. Sidewalk signs are portable a frames that are a sign base for changeable letter boards, chalkboards or poster grip sign holders. The readerboard signs can be displayed on the sidewalk, by the curb or along the road..