Adding a coating to your business cards or postcards can do many things to improve the look, feel, and overall presentation of your printed work. First, a coating will protect the ink from scuffing and improve the overall durability of your design. Second, in terms of pleasing the recipient, a coating will create a sleek and smooth look and feel. Lastly, coatings, especially if they are spot coatings, will draw the reader’s attention to particular areas, adding depth and awareness to your printed design. Below are the most popular types of coatings used in most of the print shops around the country.
Varnish is a petroleum-based variation of printing ink (ink without pigment). It will normally appear on a printing press as normal ink and applied in-line. Ink, paper type, and category of varnish (Matte or gloss, tinted or non-tinted) must all be considered when deciding on the varnish result you are trying to achieve. A gloss varnish will intensify colors on your business card or postcard, while a matte varnish has a more neutral result. Of all the coatings, varnish is the most flexible, given that they may be used on any paper stock, coated or uncoated, including text weights, and applied over ink without fear of bleeding. Varnishes applied on uncoated stock provide rub protection, but very minimal visual effect. Varnishes are slower drying than aqueous or UV coatings. Thanks to Savoir Print – Great Varnish Information
UV Coating is a very high gloss, clear liquid applied to the printed-paper surface and dried on press with ultraviolet (U.V.) light. A key benefit of UV coatings is that they are the leader in gloss and rub resistance than either varnish or aqueous coating. UV coated pieces are also abrasion and chemical resistant, providing a protective barrier against wear and tear caused by handling, display and use. Other benefits of UV coatings are low VOC [they are nearly 100% solids] and the complete, rapid cure that provides immediate drying. The limitations of UV coatings are the health hazards in handling uncured coating, poor adhesion to some inks, no FDA approval for food contact, and expensive waste disposal issues. On a per-sheet basis, UV is three to 10 times more expensive than water-based coating, depending on whether the UV coating is done in-line or off line. While UV coatings are popular on postcards and other card stocks, they are not generally efficient on lighter text weight papers. Thanks to 48HourPrint – Great FAQ
Aqueous Coating (AQ) is a fast-drying, water-based, protective coating that is applied in-line on a printing press to provide a more inexpensive coated product. This coating creates a printed piece that is resistant to fingerprints, rubs and scuffs and it lasts longer than average varnishes. Aqueous coating has the advantage over varnish due to its immediate drying. It can be applied over wet ink and seals the printed sheet, drying immediately. It will also reduce handling time for cutting and other post-press operations. Since it is water-based it has the disadvantage of causing paper curl, particularly on thinner papers. Additionally, certain pigments may bleed with aqueous.
UV vs. Aqueous vs. Varnish
Rub Resistance – U.V. coatings give the best results for run resistance. However, water based coatings also offer good rub resistance. Conventional overprint varnishes are often customized for specific requirements but, an enhancement in rub resistance is often accompanied with a decrease In gloss.
Yellowing – Both U.V. and water based coatings are non-yellowing. Conventional overprint varnishes will tend to yellow with age.
Cost – A consideration of raw material costs would show UV coatings to be more expensive than water based coatings and overprint varnishes. Water based coatings are often the most cost effective since they are applied in-line avoiding double handling. Water based coated jobs may be cut and creased after four hours.