The present invention provides a method of measuring the placement of material forming a blow-molded plastic container after the container is released from a mold of a blow molder having a plurality of molds, wherein each plastic container comprises a continuous sidewall and a base, the method comprising the steps of: detecting with an infrared camera infrared light emitted from the container after the container is released from a mold; converting the detected infrared light into corresponding electrical signals; transmitting the electrical signals to a microprocessor; comparing in the microprocessor the electrical signals with stored data regarding desired material distribution forming the plastic container; and producing output information regarding the placement of material forming the container.