Domer uses three extruders A, B, and C working together in its production line. Many co-extruded products can be achieved, such as A/B, A/B/A, A/B/C, A/B/C/A where A represents UV resins, B reprensets one color of the polycarbonate resin, C represents another color of the resin. Specific double color rate can be achieved through adjusting the extrusion speed of B and C.