What kind of paper would you like to use on your next project? If that question makes a chill go up your spine, we are here to help. Paper weight is a confusing topic, but we have the answers, and can provide you with a cheat sheet for reference, too!
When a paper is being described to you, it will have two parts, a weight and a category, such as a 60lb. Text or an 80lb. Cover. You may also see these abbreviated as 60#T and 80#C.
There are five basic categories of paper that your will deal with on press:
Writing — This common paper is used in a wide variety of applications, from business forms to household stationery. It is a strong sheet used in most copiers and desktop printers in the form of 8 ½" X 11" 20lb. standard copy paper. Also called "Bond," "Ledger," or "Duplicator."
Text — Found in books, announcements, and brochures, this is well suited for two-sided printing, very durable, and relatively inexpensive. Also called "Book," or "Offset."
Cover — Cover paper is also known as yardstick, and is a heavyweight, stiff sheet that folds and resists damage well. Because of its durability, it is commonly used in folders, business cards, greeting cards, and post cards.
Tag - Tag paper is dense and strong, used for store tags.
Index - Index paper is stiff, inexpensive and absorbs ink well, making it the prime choice for index cards and business reply cards.
So, where does the weight of the paper come from?
To determine the weight of the paper, the manufacture weighs a ream (500 sheets) of the paper's parent sheets. This is called a basis weight, and it is where we get the 60lb. in our 60lb. text. But, the 8 ½" X 11" sheets of paper that we are used to dealing with aren't the size of a parent sheet. The different categories of paper have different parent sheet sizes. Here is a list:
Parent Sheet Sizes
Writing: 17" x 22"
Text: 25" x 38"
Cover: 20" x 26"
Tag: 24" x 36"
Index: 25 ½" x 30 ½"
While different paper types have different parent sheet sizes, papers can still be compared by using equivalent weight. The table below is intended to serve as a guide only. The values should not be used as specifications, since there are variances with different paper manufacturers.
Caliper is the thickness of a sheet of paper expressed in thousandth of an inch. This measurement is taken with a micro meter. Normally, paper caliper should not have more than a plus or minus 5% variance within a sheet. Usually the greater the caliper (or the thicker the paper), the greater the paper weight, but this depends on the density and finish of the paper.
Card stock thickness can sometimes be expresses in points, as in a 12pt. stock. Points are the thickness of the sheet in thousandths of an inch, with one point equaling 0.001 inch. So, a 10 pt. cover stock is 0.010 inches thick and roughly corresponds to a weight 90 lb., or 250 g/m2 . A 12 pt. card is 0.012 inches thick.
Metric Grams Per Square Meter
Most countries use the international paper weight system that calculates grams per square meter. However, USA and Canada use the British weight system. In order to prevent any possible confusion on both sides, we provide the conversion table for the equivalent paper weight.
The metric system is standard across all weights of papers. For example, a card stock may be a 80lb. Cover or 80lb. Text. But in the Metric system, the same papers would simply be 216 g/m2 and 104 g/m2, respectively (the first being twice as thick as the second)
When selecting a paper weight, it is important to be aware that European and Asian sheets typically contain less paper pulp and more surface coating than American sheets. While an American sheet and a European sheet might both be specified as 100 lb., for instance, the European sheet would feel less bulky and would likely have less opacity than the comparative American sheet.