Explanation of paper thickness:
gsm is an Abbreviation for grams per square metre. This indicates the weight of paper, it also indicates the thickness of the paper. Generally, the higher the gsm the thicker the paper. For example: A typical photocopier paper would be 80 gsm, a good letterhead paper might be 100 gsm, a postcard would be about 250 gsm.
These sheets are folded and delivered in an A4 envelope.