What to Consider When Specifying Coated Paper
Selecting the right paper for the job may seem like a no-brainer but in actuality there are hundreds of choices to select from. Keeping it all straight can be a full time job (that's why there are spec reps). Half the battle is in understanding what to consider, so here is a brief explanation of the characteristics that go into coated paper.
Brightness is reflected light. Since the inks placed on paper are transparent, it is the paper that actually acts as a light source and supplies the light to the ink. Brightness, like the wattage of a light bulb, enhances impact and creates contrast. Thus, a sheet with high brightness will make artwork and photography pop. With lower brightness, overall contrast is reduced, and highlights are dulled.
Shade is the uniformity of reflected light across the full spectrum—in essence, the color of white. Shade determines how accurately a color image is reproduced. The “whiter” the paper, the more vibrant the highlights, reflections and contrast in the printed imagery.
Papers come in a variety of surfaces, also known as finishes. The most common coated surfaces are gloss, silk, dull and matte. Each of these surfaces provide different print qualities and overall appearance. Each has its strengths and appropriateness for a particular job. To determine the appropriate finish of the paper, we have to consider the printed piece’s desired end-result and function. For example, a gloss finish offers the ultimate in reproduction detail, while dull and matte finishes offer easier reading for large quantities of text.
Also known as “show-through,” opacity describes the amount of printed matter that is visible from the opposite side of a printed sheet. The opacity of a paper is attributable to the manufacture of the base sheet, the thickness of the sheet and chemical additives to decrease the translucence of the paper. There are two types of opacity. “Apparent opacity” refers to the actual opacity of the unprinted paper itself. “Printed opacity” is the opacity of the printed paper. It is affected by ink holdout, and is lower than the apparent opacity of the paper. This reduced opacity is actually caused by absorption of ink. As ink is absorbed into a sheet of paper, the printed opacity of the page decreases, causing the image to show through on the back which interferes with content, detail and continuity of the image being viewed.
Basis Weight and Caliper
Most brands come in a variety of basis weights in both cover and text. Basis weight is calculated using a centuries old formula based on “parent” size or trimmed sheets of paper. Five hundred sheets (a ream) of paper cut to a specific “parent” size was used to determine if the paper was destined to be bond/writing, text/book or cover weights. For example, a cover weight paper is thicker and heavier than text paper, so the weight of 500 sheets will be heavier. Nobody weighs 500 sheets anymore but the basis weight is still calculated per ream. Paper is also manufactured to a thickness, or “caliper” or point (1/1,000 of an inch) size—this is of particular importance when the final piece must meet postal requirements, which dictate either seven point or nine point thickness be used to run through postal services machines.
There are several things to consider when trying to specify a paper. That is why it’s critical to look at samples when evaluating any paper characteristics. Rely on your Millcraft Paper Rep to help you with your project. They can provide you with plain and printed samples, swatch books, and dummies - all of which can help you select the perfect paper for the job.