Abstract: A sign support comprises a rectangular sheet of a plastic material, which has two fold lines permitting it to be folded to form a closed triangular-section support member. The support member is held closed by the engagement of tongues along one side edge of the sheet engaging in slots in the other side edge, and braced by upper and lower triangular bracing members. The bracing members have tongues along each side, which engage in slots in the upper and lower edges of the folded sheet. The bracing members each have a central aperture and a slot by which they can be mounted on a lamp-post or the like, so that the support member can then be assembled round them. In an alternative construction, the support member comprises three separate sheets which can be connected together by way of tongues and slots in the opposite edges to form the closed triangular section support member.