Rosso Wholesale Glass Dealers, Inc.
Still operating today, the home page of the Rosso website says: "Welcome to Helen & Phil Rosso, Wholesale Glass Dealers, Inc. Located in Southwestern Pennsylvania since 1969. Serving Gift Shops, Antique Shops, Auctioneers, and Flea Marketers for the past 30 years and now reaching out to the online community as well."

The Rosso's will buy glass from manufacturers as a wholesaler to resell to retailers. Some of this glass, bought and sold, was iridized. Certain pieces, that the Rosso's may have commissioned the manufacturers to make specifically for them, were marked Rosso with an "R" or a capital R in a keystone.

To the right is a small iridized novelty called "Belle". Just above is the mark on the bottom of this piece.