Coatings
UV COATING
UV Coating is a clear liquid spread over
the paper like ink and then cured instantly with ultraviolet
light. It can be a gloss or dull coating, and can be used as a
spot covering to accent a particular image on the sheet or as
an overall (flood) coating. UV coating gives more protection
and sheen than either varnish or aqueous coating. Since it is
cured with light and not heat, no solvents enter the
atmosphere.
AQUEOUS COATING
Aqueous coating is more environmentally
friendly than UV coating because it is water based. It has
better hold-out than varnish (it does not seep into the press
sheet) and does not crack or scuff easily. Aqueous does,
however, cost twice as much as varnish. Aqueous comes in gloss,
dull, and satin.
VARNISH
Varnish is essentially ink without
pigment. It requires its own printing unit on press. It is
printed in-line at the same time other inks are laid down.
Varnish comes in gloss, dull, and satin (in-between dull
and gloss), and can be tinted by adding pigment to the varnish.
From an artistic standpoint, you can play a dull-varnished
portion of the sheet against a portion without varnish or with
a gloss varnish. This contrast can give emphasis to certain
areas and/or give the impression of depth.
