What is Bond Paper?

Legal Definition
Bond paper is a high quality durable writing paper similar to bank paper but having a weight greater than 50 g/m2. The name comes from its having originally been made for documents such as government bonds. It is now used for letterheads, other stationery and as paper for electronic printers. Widely employed for graphic work involving pencil, pen and felt-tip marker, bond paper can sometimes contain rag fibre pulp, which produces a stronger, though rougher, sheet of paper.
-- Wikipedia
Legal Definition
A paper that is used for writing, typing, printing, and copying. It is used for office stationary as well. It is bought by weight. It is made from 20-100% cotton. It was used for certificates originally.