Abstract: A display member (10) comprising a housing (14) having a chamber (12)with a viewing face (16) and a lamina member (24) movably mounted within said chamber (12) to be movable into a first position in which one face (26) of the member (22) in face to face contact with said viewing face (16) and a second position in which the one face (26) of the member (24) is out of contact with the viewing face (16) and the other face (25) is in face to face with a rear face (15) of the chamber (12) spaced rearwardly from the viewing face (16), drive means (22, 20) being provided to produce an attractive and/or repulsive force between said housing (14) and said member (24) to move said member (24) from said first or second position to the other position wherein no external drive means need be provided to maintain said member (24) in said first or second position, an opaque fluid filling said chamber.