Many applicators exist to apply coatings in-line at a corrugator. The boxmaker's choice is based on many -- and often conflicting -- requirements: running speeds, financial considerations, space availability, coatings to be run, etc. In-line coatings will be of two general types: functional and decorative. Functional coatings impact some type of performance characteristic to the liner or board. Examples include water resistance, grease resistance and non-abrasion. Since functional coatings are typically applied to what will become the inside of the container, they are usually applied at the singlefacer. Decorative coatings, which primarily enhance appearance, include color and white coatings and are applied at the doublebacker.
Coating equipment choices will fall into the following categories: Blade Coaters, Roll Coaters, Spray Coaters, Anilox Coaters, and Rod Coaters. The following paragraphs describe the operation of each, and the associated advantages and disadvantages.