The researchers added varying amounts of turmeric oil to biopolymer films made from cassava starch, glycerol and carboxymethyl-cellulose. Different thicknesses of the films were coated onto brown packaging paper, which was then incubated with A. niger spores. The researchers found that the films were effective, with larger amounts of turmeric oil in thicker films being better at inhibiting fungal growth. The packaging samples were also soaked in water to simulate contact with food moisture.