In the US, we measure paper’s weight in pounds while those using the metric system measure the weight in GSM or Grams/Square Meter. The Basis Weight of a sheet is the weight in pounds of 500 sheets of that particular paper cut to its basic size. Depending on the type of paper, the basic size will be different. Refer to the chart below to compare the different types of paper.

Ex. If you take 500 sheets of a cover sheet at its basic size of 20x26, and it weighs 80lbs, then the basis weight of that sheet would be 80lbs. No matter what size the sheet is cut down to (12x18, 11x17, 8-1/2x11, etc.), the basis weight of that particular sheet will always be 80lbs.
(Text Weights)
25 x 38 A versatile printing paper, used for the inside pages of brochures and books, as well as flyers, business collateral and newsletters.
COVER 20 x 26 Sometimes referred to as card stock, this sheet is heavier and bulkier than text and used as the outside cover of brochures or books, greeting cards, and projects that require a little more stiffness.
BOND 17 x 22 Commonly known as an office or business paper, used for business forms, photocopies, letterhead and stationery.
BRISTOLS 22.5 x 28.5 Lighter than index paper, this card stock typically has a toothy, vellum finish that is ideal for projects that will be handled frequently.
INDEX 25.5 x 30.5 A stiff, durable card stock with a smooth finish. Index paper is USPS 7pt or 9pt guaranteed for business reply cards or post cards.
Weights highlighted in white are the most common weights
16 40 22 27 33
20 50 28 34 42
24 60 33 41 50
28 70 39 48 59
32 80 45 55 67
39 100 54 67 82
43 110 60 74 90
47 119 65 80 97
53 134 74 91 110
58 146 80 100 120
65 164 90 111 135
67 171 93 115 140
72 183 100 123 150
79 201 110 135 165
87 220 120 148 180
94 238 130 160 194
Grain Direction
Grain direction describes whether paper fibers run in the direction of the long dimension of a sheet (grain long) or the short dimension of a sheet (grain short). Why does it matter? Strength. It’s easier to cleanly tear a sheet of paper with the grain, and folds parallel to the grain direction will be less likely to crack and fray.
A sheet referred to as toothy will have a surface with a subtle roughness. Tooth is important to consider when printing as it typically absorbs more ink than a smooth surface.
During the papermaking process, a continuous sheet of paper passes through steel rollers, also known as calender stacks. The polished steel rollers apply pressure and heat to the sheet in order to make the surface smoother and glossier. The more pressure and heat the rollers apply to the surface, the smoother and glossier the sheet.