A Kraft corrugated boxes are sturdy and food safe, so no varnish or coating is required.
However, corrugated packaging can still cosmetically benefit from coatings to enhance artwork designs. Varnish and Aqueous (AQ) coatings are most popular for corrugated packaging.
AQ coating is a water-based coating that is fast drying and eco-friendly. On the other hand, Varnish is not eco-friendly but provides an optimal moisture barrier to protect your products and artwork designs. Both AQ coatings and Varnishes allow for either a matte or glossy finish.