Paper & Envelope Sizes – Grammes to Microns – Storage

A range of common paper sizes, an explanation of gsm and microns and advice on paper storage.

Paper Sizes

 A Sizes                           SRA Sizes                             Envelope Sizes

A0  – 1189mm x 841mm   SRA0 – 1280mm x 900mm   C3  – 457mm x 324mm
A1  – 841mm x 594mm   SRA1 – 900mm x 640mm   C4 – 324mm x 229mm
A2  – 594mm x 420mm   SRA2 – 640mm x 450mm   C5 – 229mm x 162mm
A3  – 420mm x 297mm   SRA3 – 450mm x 320mm   C6 – 162mm x 114mm
A4  – 297mm x 210mm   SRA4 – 320mm x 225mm   DL – 220mm x 110mm
A5  – 210mm x 148mm
A6  – 148mm x 105mm
A7  – 105mm x 74mm
A8  – 74mm x 52mm

GSM and Microns
Board thickness or caliper is measured in microns (1000 microns = 1mm).  Most of the time boards are referred to by weight in gsm (grams per square metre).  A few different board weights are shown below along with their thickness in microns – although depending on the finish of the board this may vary. For example, a coated shiny board will be more compressed and therefore thinner/lower in microns, whereas a pulp or textured board will be thicker.

160gsm = 200 microns
180gsm = 230 microns
240gsm = 300 microns
270gsm = 350 microns
290gsm = 380 microns
385gsm = 500 microns

Storage
Paper is liable to be affected by variations in temperature and humidity.  The optimum storage conditions are a temperature of 16ºC – 22ºC and relative humidity (the moisture content of the air) of 40% – 60%.  Variations in humidity are the most serious and can, by changing the moisture content of the stationery, permanently damage it.

Stationery transferred from a cold room to a warm room can experience a temporary warp.  Sufficient time should be allowed for it to become acclimatised before being used.

All printed stationery should be kept in the original boxes until required for use.  The boxes should be stored lid uppermost and should not be stacked more than five high.  Any partly used box should be placed as the top box.

Stationery should not be stored directly touching the floor and should be kept away from pipes, radiators, hot air ducts, windows or such like.