TY - GEN TI - "Invisible joint" (trade mark) metal ceilings and side walls - Lock Joint-Colonial, Design No. 1955. AU - Milwaukee Corrugating Company. Art Metal Ceiling Department DA - 1920s UR - https://digital.lib.uh.edu/collection/aapamphlets/item/1877/show/1611 Y2 - March 4, 2021 ER -