New Page has a great educational series on all things print called Ed. The following is from their site, edliveshere.com
to read the full article click here. To request your copy of Ed, go to millcraft.com
Like Bob Dylan says, “Every man needs protection.” And so do many print projects. But even though protection may be necessary, it’s often overlooked. While a great deal of ink has been devoted to preparing words and images for the press, much less attention has been paid to preserving the work after it leaves the printer. Aside from using a varnish to highlight a photo, designers often give little thought to the use of protective coatings or laminates (sometimes called lams by their friends). And clients may not ask about them at all.
Ed believes it is time to fill this knowledge vacuum—to end what might be called the silence of the lams. And the place to begin is with some definitions.
Liquid coatings are applied in-line by the printer as part of the printing process or off-line, after the project leaves the press. While some coatings, such as varnish, can be spot applied to a precise point or points on the page—just the photos, for example—other coatings, including aqueous coatings, are usually flooded across the entire sheet. Different coatings are available in different finishes, tints, textures and thicknesses, which may be used to adjust the level of protection or achieve different visual effects. Areas that are heavily covered with black ink often receive a protective coating to guard against fingerprints, which stand out against a dark background. Coatings are also used on magazine and report covers and on other publications that are subject to rough or frequent handling.
Film laminates are usually applied by finishers or converters that also offer die-cutting, embossing, foil stamping and other such services. The film may be applied using either a wet method, which relies on solvents, water or both, or the more environmentally friendly thermal method, which uses heat to iron the film and paper together. Either way, the entire sheet is generally laminated—there is no practical way to spot laminate a project.
Lamination films are available in a variety of tints and textures, and there’s even a lenticular film designed to help create a holographic effect. The films are classified by thickness, which is measured in mils, or thousandths of an inch. The thinnest films, typically around 1.2 mils, are used on items that are rolled or folded. Heavier films, of up to 10 mils, leave a heavy plastic coating on the sheet that can stand up to anything short of a small but determined Rottweiler. The laminates can be applied on one side or both sides of the paper, and with a sealed edge, which makes the sheet virtually waterproof.