A method of manufacturing a golf club head with a variable thickness face having a central thickened region surrounded by a transition region tapering from the central thickened region to a thinner peripheral region. Each picture processing system includes an identical picture processing IC and a plurality of memories each capable of memorizing a picture frame and including at least two memories operating at different timings. The flooring is then laid and consists of a floor foundation, a decorative finishing coat, a transparent resin topping with anti-slip characteristics and an anti-scratch and anti-wear blanket. the sleeve is inserted into the receiving holes of the top article and the bottom article until the outer flange of the top end rests on the top plate, the rod is then pressed to move to drive at least one spring tab to deflect outwardly until the outer flange of at least one spring tab is held in contact with the bottom plate. The loop heat pipe circulates heat emitted from the image display unit to equalize the temperature of the image display unit. The method further includes subsequently performing the epoxidation reaction at a preferred operating condition.