A stamp adapted for connection in a series, the stamp comprising a handle having a rubber letter or figure overlaid to a non-porous first rubber layer and a second porous rubber layer; and the handle having a first tenon and a first mortise on one side, and a second tenon and a second mortise on the opposite side, the first tenon being adapted to fit in the second mortise and the second tenon being adapted to fit in the first mortise.