Abstract: A polymer molding system and method of operation produces synthetic article of manufacture that simulate natural building materials such as wooden shakes and stone roofing tiles. The system preferably feeds at least two dye compounds and a polymer filler material into an extruder for heating into a ribbon. The ribbon is heated as it travels through the extruder and through an outlet end where a slicing unit cuts the ribbon into a plurality of preforms at a pre-defined rate. Because the dye compounds are not homogeneously mixed with one another, the ribbon and hence the preforms are generally of at least two colors. Each preform is individually fed into a press that stamps and partially cools the preform into the simulated article of manufacture shape that also accentuates the varying colors. Preferably, the stamped article is then flexed or cupped between a carriage and a dead weight prior to crystallization and where it then cools and crystallizes to a final shape.