Reverse printing (sandwich print)

Reverse printing means printing a mirror image on the inside face of a clear outer film (usually PET or BOPP) and then laminating it to an inner layer, so the ink is trapped between the two films.

Benefits

• The print is protected from scuffing, moisture and grease.
• Ink does not touch the food or the consumer's hands.
• The glossy outer film gives the graphics depth, as if under glass.
• Sealing jaws and filling machine parts cannot damage the print.

Compared with surface print

Surface printing puts ink on the outside. It is cheaper and used on single-layer packs, but it is exposed and often needs an overprint varnish. Reverse printing requires at least two layers and a lamination step, adding cost and some curing time.

Good to know

You do not need to mirror your artwork; prepress does it. A white underprint is printed last, behind the colours. Most laminated doypacks, flat-bottom and quad-seal pouches use reverse printing as standard.