Good optical properties, such as high gloss and transparency, are essential for
bag, pouch and top web materials to satisfy consumer demand for a clear view
of the product. To provide attractive appearance and shelf impact, some base
tray materials are available in various colours. This also enhances the visual
appeal of the product against the tray and helps consumers to identify product
ranges and brands on the supermarket shelf. PET, PP and EPS trays are
supplied in a range of colours. PVC trays are generally used in their natural
form to provide a transparent pack.