I made this bag using plain white cotton. Soaked the cotton in a thin mix of PVA glue and water first. Then when dry I stamped the images and coloured them with Promarkers. Then I gave the bag a final coat of matt medium to seal.
This bag is made by stamping the plain white cotton and then adding some sticky bag plastic book film to the fabric. You then iron the film to seal it into the fabric (you need to sandwich the fabrics between greaseproof or baking paper to protect your iron and ironing board and iron very very carefully on a low to medium heat otherwise the plastic burns). Finally I coloured the whole thing with promarkers.