When Domtar manufactures copy paper there are at least 20 critical variables to control to ensure that the product performs to the customer’s expectations.  A variable that most consumers are familiar with is the basis weight.  It’s listed on the packaging and sometimes it’s referred to when describing the product.

This article will define how basis weights are calculated for different types of uncoated papers, highlight the most common weights used in an office environment and point you to an online calculator that converts basis weight to GSM.

Basis weight is the weight in pounds per ream of paper cut to its basic size. A standard ream is defined as 500 sheets.  In office papers the majority of usage and production is paper with a basis weight of 20lb.  If you have ever wondered why the ream of a standard sheet (8 ½ x 11) of 20lb paper feels lighter than 20lbs. It’s because it is lighter than 20lbs.  Copy paper falls into the Bond Paper category.  The basic size of bond paper is 17 x 22.  So, 500 sheets of 17 x 22 weighs 20lbs. 500 sheets of 8 ½ x 11 weigh 5 pounds.

Here is a list of all grades that are potentially used in office printing.

Type of Paper (basic size)

Book & Offset (25 x 38)

Bond & Writing (17 x 22)

Cover (20 x 26)

Vellum Bristol (22 ½ x 28 ½)

Index (25 ½ x 30 ½)

Quill has a more detailed chart that lists the basic sizes by types of paper and references the common applications for each grade.

Click to Enlarge Image

Within the office paper category 20lb is the most common weight used and is sufficient for most standard copy applications. When the need calls for something heavier, there are options. The next step up for office paper is 24lb. Use of a heavier basis weight can be helpful when the print coverage is greater than normal or the printing is two-sided, also called duplex.  The extra basis weight helps to minimize the show-through.

When color printing is in play with the use of ink jet equipment or color copy toner devices it is sometimes desirable to have even more heft.  If you are printing with color, chances are it’s for a document that you want to get noticed. It is in this realm where you will find the heaviest of office papers. For bond weights, premium business paper grades, like Xerox^® Bold Professional^® Premium Quality Printer Paper, are often available in 28lb & 32lb.  In addition, the premium grades usually have cover weight options. The most common cover weights for office printing are 60lb, 80lb and 100lb.

Most printing equipment used in the office environment will have recommendations on the maximum weight of paper that will fit through the printing units. The recommendations are typically listed as GSM (Grams/Square Meter).  Domtar lists the gsm next to the basis weight on their packaging. (See image).

If you need to evaluate a cover option against the OEM recommendations before you purchase the paper and you don’t know the gsm of the paper stock, Domtar offers an online grammage calculator to convert between standard and metric. Here’s a screenshot using the example of an 80lb Cover stock.  The gsm for 80lb Cover equals 216 grams. The blue drop down includes all the basis sheet sizes for the types of paper in our list above.

For most office printing equipment you will not have any limitations using bond weights: 20lb, 24lb, 28lb, 32lb.  When you enter the world of covers, which includes Index and Tag plus true Cover paper, it’s best to check the gsm limits of your printer. Now that you have the lowdown on basis weights you can possibly add a little variety to what you feed through your printing devices.

For more information on our office papers, visit Domtar.com.