What is paper thickness?
In printing industry, when talking about paper, thickness is usually mentioned. Pt is often used to describe paper thickness. 1 pt means 0.01 inch, 10pt presents 0.01 inch and 20pt means 0.02 inch. Business card is a good example of papers with different thickness, most of which are printed on cover paper of 12 or 14pt, while super thick card is printed on paper of 18t, 24t or even thicker. There are some other products usually printed on thick paper such as tag, door hanger, bookmark and packaging.
What is paper weight?
Paper weight is hard to define. Paper weight can be defined in different ways according to distinct countries or regions.
Paper is weighted through weighting 500 sheets stacked together and the obtained weight is weight identification of paper. For example, if text paper weight of 500 sheets stacked together is 60 ponds, we call it 60# text paper. If cover paper weight is 120 ponds, we call it 120# cover paper.
Most of time, paper weight is higher when it is thicker.
There are also some thin paper with high weight. For example:
60# text paper: used as copies and printing paper
80# word paper: used as leaflet, posters and booklet
120# cover paper: basically thin cardboard, used as postcard, business card and script paper