When it comes to coated vs uncoated paper, the main difference is the way the paper is manufactured. Coated papers have a coating on them (typically clay), so they’re “sealed.” This restricts the amount of ink that is absorbed into the paper, allowing the ink to sit on top of the paper, in a crisp defined dot.
Uncoated papers do not have this coating and thus are more porous. The ink soaks into the paper and has a softer, warmer appearance. Uncoated papers are categorized by type: offset, opaque and text & cover. Domtar’s line of papers fall in the offset & opaque categories, with Cougar being a premium opaque sheet.
Coated papers are categorized in two ways; by their finish: gloss, dull, silk or matte or by quality (brightness and price): Premium, No. 1, No. 2, No.3, No.4, No. 5. A coated paper with brightness of 88+ is classified as a premium paper. The higher the brightness level, the more light that bounces off the sheet. Most inks are transparent, so the reflected gives the appearance of bright, crisp vivid image. With coated papers, the glossier the finish, the less ink absorption.
Uncoated white papers too are defined by their brightness levels – the brighter the sheet, the more light reflected back to the eye. For example, Cougar is a 98 Bright white sheet, meaning 98% of the light is reflected back to the eye of the viewer. This level of brightness helps four-color images “pop” off the paper as the lights reflects back through the ink.
Uncoated papers can have many finishes to them: smooth, linen, laid, vellum, and super smooth just to name a few. The smoothness level is an important factor when considering uncoated papers as it is not only what gives the paper its feel, but also affects ink holdout. The smoother the sheet the more even the ink lay. This is especially important when printing areas of heavy solids or metallic inks.
Coated vs Uncoated Paper – Choosing the Right Type of Paper
When it comes to deciding on which type of paper to use for your next print project, considering aesthetics, functionality and budget will determine the best one.
Coated papers offer excellent ink holdout and perform well with areas of heavy solid color and metallic inks. Their surface, regardless of the finish, work well with techniques like varnishes, UV coatings and foil stamping as design elements – even with a subtle clear foil.
Uncoated papers work well with pressure based print techniques like embossing/debossing, letterpress and foil stamping. They provide a nice contrast between the surface of the sheet and the impression. They lend themselves well to folding, even on heavier weights (fold with the grain); and are an excellent choice for tactile packaging applications.