# Lab Filtration glossary

## Basis weight

Weight of a sheet, usually expressed as g/m2 (at a predefined level of moisture content or conditions of measurement).

### FAQ Weight of a sheet, usually expressed as g/m2 (at a predefined level of moisture content or conditions of measurement). Mass per number of sheets:“20#” is “20 pounds per basis ream of 500 sheets”. Often, if the density of a ream of paper is measured in pounds, it can go together with the “M weight”. The M weight can be known as the weight in pounds of 1000 cut sheets.Gramm per square meter:GSM is the substance weight of paper. An area of paper that is constant and is not affected by the size of the sheet, relating to the GSM. The measurement is expressed as grams per square meter. (A typical paper is usually 80gsm).

Weight of a sheet, usually expressed as g/m2 (at a predefined level of moisture content or conditions of measurement).

Mass per number of sheets:“20#” is “20 pounds per basis ream of 500 sheets”. Often, if the density of a ream of paper is measured in pounds, it can go together with the “M weight”. The M weight can be known as the weight in pounds of 1000 cut sheets.

Gramm per square meter:GSM is the substance weight of paper. An area of paper that is constant and is not affected by the size of the sheet, relating to the GSM. The measurement is expressed as grams per square meter. (A typical paper is usually 80gsm).