Chitosan (varied from 1 to 4% (w/v)) was dissolved in 2% (v/v) acetic acid solution and stirred by a magnetic stirrer at about 700 rpm until the dissolution was completed, which typically taking about 2–3 h. The solution was then filtered prior to coating application. Coating chitosan solution (about 30 mL) onto the starch film was carried out by an automatic film coater with wire bar coating rod number 75(Tester Sangyo Co., Ltd (Japan)). After coating, the acrylic mold support containing chitosan-coated starch film was taken out from the automatic film coater and stored at room temperature, allowing the coated film to dry for at least 72 h. The coated film was peeled from the acrylic mold and measured thickness by micrometer. The dry coated film thickness was fallen within the range of 0.08–0.12 mm.