Optional clear coatings are often applied over the ink on printed pieces to protect them from scuffs and abrasions. Coatings are recommended for pieces which are handled frequently, like brochures. In addition to protection, gloss coatings enhance the appearance of printed pieces by giving them some sheen, which in turn helps make colors appear more vivid. Conversely, matte coatings offer protection but little or no sheen. Coatings will not guard against long term color fading or provide protection from outdoor weather.
If a printed piece is not coated, it will have a flat finish. Depending on the design or function of your printed piece, a flat finish may be desirable. For example, letterhead and envelopes are left uncoated because you will need to type or print on them and a coating would inhibit the absorption of the ink you apply. Also, business cards are sometimes left uncoated to match the letterhead and envelopes.
As the name implies, Aqueous Coating is water-based. It can be applied over wet ink while the job is still on-press. It dries fast, thus reducing the handling time for post-press operations such as cutting. It is an economical coating and is available as gloss, dull or matte.
Ultra-Violet (UV) Coatings are available in various gloss sheens or dull. UV is commonly used to provide a high gloss sheen to promotional pieces. UV is applied as a secondary operation off-press. It dries instantly when exposed to ultra-violet light. It provides more protection than Aqueous coating but generally costs a little more. UV Coatings are particularly popular on postcards, heavy weight brochures and other card stock projects. UV is not generally used on lighter text weight papers. Because it is a thick coating, folding operations will generally require pre-scoring to reduce cracking.