A method of tuning or trimming a flexure stage to substantially constrain a workpiece carried by the flexure stage’s free end from moving along an axis of motion that does not contain a desired path of free end travel. The process may be used to spray form articles having a skin formed from a polyurethane composition. More specifically, the solid-particulates-containing composition comprises 5-80% by volume of the chosen particulate solid dispersed within either a vinyl acetate polymer product or an acrylic polymer product, there being, per 100 volume parts of the chosen polymer, from 25 to 80 parts of water. In another embodiment a continuous ribbon of dampening fluid may be applied directly to the reimageable surface.