The Mystic Stamp Company is a mail-order postage stamp dealer, one of the largest in operation and notable for both its promotion of stamp collecting as a hobby and for its acquisition of the Z Grill, the rarest United States stamp. Based in Camden, New York since 1923, the company deals primarily in US stamps and supplies.
Like most stamp dealers, sales of stamps and postal products are made through printed catalogs as well as an online catalog that have the details of all the current stamps on offer.
At the Siegel auction of the Robert Zoellner collection in 1998, Mystic president Donald Sundman acquired the Z Grill for $935,000, the highest price ever paid for a US stamp. Subsequently Mystic made good use of its acquisition, featuring it in company advertising and listing it for sale in the catalogs.
In late October 2005 Sundman traded the Z Grill for the unique Inverted Jenny plate block, worth nearly $3 million, from U.S. financier Bill Gross, thus giving Gross the only complete collection of US stamps.