I promised I would tell you more about my search for 18th century stationery, so here it is.
Stationery, meaning specialized paper products, has been around since the Middle Ages at least and was once the domain of stationers who had permanent shops mainly near Universities and government centers where paper usage was at its highest. They were responsible not only for paper supply, but also for publishing and copyright privileges. While beautiful and customized stationery would not become truly de rigeur until the Victorian era, nice handwriting and good quality papers and seals were still a recognized status symbol in the 18th century.
Here are a few modern options for those fine writing supplies you'll need in all of your correspondance.
Sullivan Press has a set of paper, ribbon, quill and ink available in the style of the Revolutionary War era. Includes instructions on creating envelopes and examples of calligraphy. Retails for $7.50.
Want something a little more whimsical? Check out these Marie-Antoinette-inspired cards from Paper Nosh. They are part of an entire series of 18th-century themed stationery; cards, paper, invitations, and postage. They even come custom-wrapped in beatiful boxes with bows for no additional charge.
Got wax? These chess-piece shaped seals are reproductions of 18th century chess pieces and come custom-cut with your very own design. $150.00 each from Wax Works.