A riblet forming system incorporates a gantry which supports a laser and a paint applicator is positioned and moved over an aerodynamic surface. A computer control system is connected for control of the gantry on a predetermined path over the aerodynamic surface and further connected to the laser to control cutting a riblet topography along the predetermined path in a predeposited paint layer.

A method of molding an article includes positioning a dissolvable insert within a mold, filling the mold with material to form an article within the mold and about the dissolvable insert, and at least partially dissolving the dissolvable insert from within the article. The dissolvable insert forms internal features of the article and includes a porous core.