PROTECTIVE COATINGS

What are "after print" coatings like U/V and A/Q and why are they desirable?

• U/V is a clear liquid applied after printing and dried and cured instantly using U/V lights.
• A/Q is a clear water-based liquid applied after printing and dried and cured using Infra-Red heat lamps.

The three most common reasons for adding U/V or A/Q coating to a printed project are...

• protection - to avoid scuffing the ink, especially with heavy ink coverage
• aesthetics - to draw the reader's eye to a particular item or items
• to improve reader response through added impact, depth and interest.

Coatings like U/V & aqueous (A/Q) offer:

• protection against fingerprint marking on dried inks, especially in dark solids
• elimination or reduction of scuffing caused by items shifting around in transit

U/V coating is applied as a separate finishing operation and:

• is available in gloss or dull finish
• can be applied as a "flood" or "spot" coverage
• gives more protection and sheen than aqueous (A/Q) coating
• cured with light and not heat so no solvents enter the atmosphere
• is more difficult to recycle than A/Q
• may crack when scored or folded

U/V coating is generally spread as a flood coating over the entire printed page and then dried and cured instantly with ultraviolet light. Optionally, it can also be applied as a spot covering to accent a particular image on the sheet.

Aqueous coating (A/Q) is more environmentally friendly than U/V coating because it is water based. It does not seep into the press sheet and does not crack or scuff easily. Aqueous does, however, cost twice as much as varnish.

Since it is applied by an aqueous coating tower at the delivery end of the press, it can only be laid down as flood aqueous coating. It is not available as a localized "spot" coating. Available finishes include gloss, dull, and satin.

When considering using U/V or A/Q, keep in mind the following:

• Not all printers can apply U/V or A/Q coating
,
• You cannot print (ink-jet or by hand), glue, or foil stamp over coatings
,
• Only apply U/V or A/Q coatings to coated paper.
• The application of U/V or A/Q coating is expensive and requires specialized presses and/or stand-alone coating equipment.
• If you want to print (ink-jet or by hand), glue, or foil stamp a product after it has been printed, leave an uncoated window or page.
• Only apply U/V or A/Q coatings to paper that is supplied coated with a dull or gloss finish. This paper factory finish will prevent the U/V or A/Q coating from seeping into the paper fibers and be lost.