Equivalent Weight

While different paper types have different basic sizes, papers can still be compared by using equivalent weight. In this chart a 24 pound bond has the equivalent weight as 60 pound offset.

With all the new digital equipment coming out lately things are trending toward Metric, grams/sq meter (gsm) see the last column to find its equivalent. I know, it was all very confusing to me too. Until I received this chart from one of my vendors. Give me a call or send me a message if you'd like me to e-mail it to you.

Basis Weight

The basis weight of a paper is the weight of 500 sheets, measured in pounds, in that paper's basic sheet size. It is important to note that the "basic sheet size" is not the same for all types of paper and it is never 8.5 x 11. 8.5 x 11 is the result of cutting a basic sheet of "bond" paper.
source: www.paper-paper.com

Caliper

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 throughout the sheet run. The greater the caliper the thicker the paper, or the greater the paper weight, but this depends on the density of the finish as well. Dull will have a greater caliper than gloss, and feel thicker to the touch, but both gloss and dull finishes will have the same weight.
source: www.paper-paper.com