The stationery system used by a business or professional organization.

printed name and address on stationery; a printed heading for official stationery, usually containing a company's name, address, telephone and fax numbers, and often including a logo and other details.

a sheet of stationery with name and address of the organization printed at the top

Business stationery and envelopes imprinted with the company's (or, in such a case, the writer's) name, address, and logo - a convenience as well as an impressive asset for a freelance writer.