What is the difference between Micron and Grammage?

Question

when determining the thickness of paper or card.

I don't suppose there is a formula for coverting between the two?

sorry bad spelling -- converting !!

Answer 1

Traditionally in the paper trade grams per square metre g/m2 (sorry haven't found out how to put symbols in here should be a small high 2) was used for paper and microns (thickness) for card. The dividing line was 160g/m2 or 200microns.

When photocopiers and other office printers started to be introduced the manufacturers quoted all paper tolerances by weight and this is starting to become the norm.

It is quite a good idea but thickness will vary between papers of the same weight because of different substances used to make different grades. For instance glossy art papers are made using china clay which is heavier than paper pulp. There is therefore no way to convert one measurement to the other. Sometimes paper merchants give both measurements but usually not and they are no longer consistent with the paper/card rule.

If there is a specific paper you need to know about try the manufacturer's web site and send an enquiry.

Answer 2

micron is a single dimension
gramage is a weight
...two differnet measurement types

so micron is the actual thickness of the paper
grammage is the weight of the of paper for a given area.

effectively both resolve back to the same properties. the paper standard is quoted as n grams (but you could also express that as the true thickness of the paper)

Answer 3

Micron is the measure used for thickness. Grammage is the weight usually per square metre. So if thickness is what you require then check for micron value.