Coating the sheets with chitosan led to a higher surface roughness compared with the uncoated sheets, independently of the method used for coating. This feature may be associated with the reaction of glutaraldehyde with repeating units of the chitosan polymer chain due to the cross-linking process. Furthermore, the sheets coated by immersion showed a more irregular surface than the spray-coated samples, probably because the immersion favored water diffusion into the starch matrix which modifies the surface appearance of the sheet.