Paper Lingo
Paper Weight
The weight of paper is measured in the Uk and in Europe as grams per square metre. This is nearly always abbreviated and displayed as 'GSM'.
Generally the rule is, the heavier the paper, the thicker it is. Paper weights usually run up to 170gsm or 200gsm (max), and board weights are anything above.
gsm
=
grams per
square metre
Paper Surface
eg; 150gsm (1.3 Bulk) = 195 microns
Paper Surface
μm
Microns
=
Bulk
The 'bulk' describes a papers' thickness and is sometimes referred to as it's caliper.
Microns are the metric unit used to express a papers' thickness. A micron is one millionth of a metre, and measured using a device called a Micrometre.
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The sysmbol used is μm
Grain Direction
The Grain Direction plays as much of a role in paper as it does in wood.
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The direction of the grain is determined by the direction in which the wire on the paper machine is travelling when the paper is being made.
The grain direction will affect things like creasing, folding and rigidity. The direction of the grain can be either Short Grain or Long Grain. Most papers on sale to the general public are Long Grain.
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Short Grain = Grain running parallel to SHORT edge.
Long Grain = Grain running parallel to LONG edge.
grain
direction
=
direction of fibres
A4
Long Grain
direction of grain
297 mm
210 mm
A4
Short Grain
direction of grain
210 mm