Category and standards

Paper Sizes

Standard paper sizes like ISO A4 (ISO is an international standard-setting body) and its standards are widely used all over the world today.

ISO 216 specifies international standard (ISO) paper sizes used in most countries. The standard defines the "A" and "B" series of paper sizes, including A4, the most commonly available size.

A0 841 x 1189
A1 594 x 841
A2 420 x 594
A3 297 x 420
A4 210 x 297
A5 148 x 210
A6 105 x 148
A7 74 x 105
A8 52 x 74
A9 37 x 52
A10 26 x 37

Weight of Paper

The weight of a sheet of paper or card is the thickness of that piece of paper.

The weight of paper in countries that use ISO paper sizes is defined by ISO 536 Paper and Board - this standard means grams per square metre (g/m2).

For Example - an A0 sheet of 80gsm paper will weigh 80 grams, an A0 sheet of 100gsm paper will weigh 100 grams and so on.


Thickness is measured in microns, or thousandths of a millimetre.

  • Newsprint is 45 gsm - 70 microns,
  • copying paper 80 gsm - 100 microns
  • thin cardboard 180 gsm - 200 microns
  • cardboard 400 gsm - 600 microns.

Card thickness (caliper) is measured in microns (1000 microns = 1 mm)

Although weight and thickness usually correspond; it is not always the case. For instance, embossed card with a raised design may be thicker because of the embossing, but not necessarily heavier.


2-sheet / 200 microns / 150-160 gsm

Thin card used for photo copiers

3-sheet / 230 microns / 170-180 gsm

A little thicker than copier card, not quite firm enough to use as a card base, but good for layering and die cutting.

4-sheet / 280-300 microns / 210-240 gsm

Medium card, but feels thin and a bit flimsy. Not suitable for larger card base as it will bend.

6-sheet / 350-380 microns / 270-290 gsm

Thicker quality card suitable for invitations and good for folded card base.