A universal object holding mechanism for holding three-dimensional objects for printing thereon uses multiple conformable balls mounted within a pattern of holes in a two part back plate. The multiple conformable balls are pressed into an object, which in turn, is pressed against a datum surface that represents desired spacing away from print heads. Vacuum is applied to the multiple conformable balls which grip the object. The multiple conformable balls are filled with particulates that cause the multiple conformable balls to become rigid when the vacuum is applied. This contributes to keeping the object from moving when it is being moved past a print head.