A screen printing apparatus for printing images onto a three dimensional surface of a substrate. The apparatus includes a screen formed of a flexible mesh material and having porous image portions that allows passage of a printing medium through it. A shaping assembly including a plurality of shapers that are movable between retracted and extended positions. In their extended positions, the shapers are engaged with the screen assembly and generally cause screen to generally conform to the three dimensional surface of the substrate. A squeegee, that is flexible and conformable to the three dimensional surface, is drawn along screen and forces at least some of the printing medium through the porous portion of the screen and onto the three dimensional surface.