VARNISH

Varnishes are essentially “clear inks” with the same viscous quality as press inks. They come in gloss or dull finish and are most adaptable to creative design effects using combination spot finishes to contrast and highlight images. Press varnishes are solvent-based and dry relatively fast by oxidation. Varnishes are applied like ink, from roller, to plate, to blanket, to sheet, in-line, on press. Varnish, the least expensive final finish, is usually designed to seal the ink, and protect the carton during the final finishing stages and on the shelf. They can be formulated as “wax-free” to accept hot foil stamping, but will have less rub resistance that standard high gloss varnishes. High gloss box varnish provides moderate rub resistance, but caution should be used in shipping heavy products in varnished cartons to prevent scuffing.

AQUEOUS COATING

Aqueous coatings are waterbased liquid coatings similar to varnishes but with harder resins. These coatings can be applied either in-line, on press, or as a separate off-line coating. Aqueous coatings provide a slightly higher gloss finish and smoother feel than gloss varnish, as well as a greater rub resistance. Aqueous dries by oxidation and with the use of heated air can dry as quickly as 10-15 seconds, which reduces the need for non-offset powders. Aqueous is typically glueable and therefore can be applied to the sheet as an overall coating, but it can also be applied as a “spot” coating with the use of a relief plate or blanket.

MARCOTE

This is a viscous polyester-based catalyzed liquid coating, which is heatset by ovens to evaporate the solvents and harden the coating. It is roller-applied off-press by special equipment. Marcote has a higher gloss than varnish, but lower than U.V. Coating and is less durable than U.V. or film lamination. Marcote can sometimes diminish chemical ghosting or hazing problems that may occur in the printing process. It is available in gloss finish only, and does tend to yellow colors somewhat.

U.V. COATING

This is Ultra-violet cured coating. It is a liquid coating that uses U.V. lights to harden the coating as opposed to drying by oxidation. It is generally either roller applied off press, or if spot U.V. is necessary can be applied by a type of silk screen process. Other than film lamination, Gloss U.V. gives cartons their highest rub resistance and highest gloss. It is also available in matte finish. It is higher in cost than regular press varnish, and specially formulated inks must be used if the colors would normally contain Rhodamine red or Reflex blue. UV coating is used for its high gloss and excellent rub resistance. ONE NOTE OF CAUTION: While UV coating will generally enhance the look of the colors on the printed sheet, it often affects the final color, even when specially formulated inks are used. We will take every precaution to minimize this change, but not even the coater can predict the final result since the color may change up to 12 hours after the coating is applied. PMS or specially matched colors are at particular risk, and the same ink on the same board will often come out a somewhat different color on different runs. The white of a board can also turn slightly yellow after UV coating. These are changes that the existing technology cannot yet overcome, and Sierra Packaging cannot accept responsibility for UV caused color changes.

BOOK LACQUER

This is a solvent based, oven-set liquid lacquer coating. It is a roller applied, full-coverage process done off-press on special equipment. It is often recommended when a satin finish is desired but is also available in gloss. Depending on the stock, book lacquer gloss finish is about the same gloss level as Marcote or U.V. coating. The satin finish has a little more sheen to it than U.V. matte or the film lamination matte finishes.

FILM LAMINATION

A full-coverage, film-to-sheet, lamination process versus the roller-applied, liquid coatings. The film, of usually .0015” thickness is pulled over the sheet, laminated, and adhered to the stock. This process gives the greatest level of gloss, moisture and scuff-resistance and actually strengthens the sheet. Available in gloss and matte finishes, it can be used on folding cartons up to .024. The matte finish is more velvety than other matte finishes and imparts a “cloudy” effect softening the printed colors. Film lamination is the most expensive of all the final coatings mentioned.

NOTE:

These are general descriptions and are not an all inclusive list of the finishes available in the folding carton industry, just those available to Sierra Packaging, Inc. The most common and most cost effective is the aqueous coating, which is applied in house. The other finishes listed are applied by an outside supplier and do increase the cost. The relative costs of the other finishes will vary according to the sheet size, length of run, and any set-ups involved. U.V. coating is generally the most versatile and used more often than the others.