Abstract: Apparatus and methods for testing printed metallic can body members for defects by the use of light involving gravity infeed apparatus for locating can body members in separate pockets on a continuously rotating transfer wheel, seating apparatus for seating the can body members in the pockets, testing the exterior surface of the can body member for the presence of printed ink thereon, axially displaceable can body member support apparatus for axial displacement of the can body members relative to the pockets and the transfer wheel to locate a flange portion in sealed association with a resilient deflectable sealing member, application of vacuum to the bottom of the can body member to hold the can body member on the support apparatus until release of the vacuum, application of pressure to and pressurization of the sealing member and the inside of the can body member; location of the pressurized can body member in a zone of florescent light, location of the can body member relative to light detecting apparatus