Stock Wieght Stock thicknesses based on the weight of a 1-metre square which is translated to GSM (Grams per Square Metre). The weight doesn't always resemble the thickness as some papers have been made to be more dense of fluffy. They majority of the time this doesn't apply and the gsm does give you an idea of thickness. it is very important to grasp the fundamentals of when to use certain weight of stocks to be successful withing graphic design. Here is a quick guide of what different thickness are used for in the industry. 90 - 100 gsm - used for stationery, text for magazines and booklets, flyers and brochures. 120 -170 gsm - used for text for booklets, flyers and brochures. The heavier the weight, the more "upmarket" the feel. 200 - 250 gsm - used for magazine and booklet covers. Robust enough to give some body and stiffness when used in a publication, but not quite heavy enough to be used on its own for cards etc. 280 - 300 gsm - used for cards of all sorts and book and booklet covers.