I just received an email from a new Roseville pottery collector asking "Is this Roseville vase a factory second because it is marked with an X?"  While Rookwood pottery, some Scandinavian makers, and many other pottery companies including contemporary potters such as Ephraim Faience use an "X" mark to indicate factory seconds, at Roseville Pottery the letter "X" did not indicate a particular vase was of substandard production. 

It is believed by most Roseville pottery experts that the letter "X" mark on Roseville pottery was used to indicate a specific firing schedule.  As an example, the following photos show three Roseville Velmoss pieces each of which was marked from the Roseville factory with an underglaze "X".  None of these three examples exhibit any noticable factory flaws or irregularities.  Page 275 of Mark Bassett’s Introducing Roseville Pottery provides an additional example of the "X" mark and short discussion of the theory that the letter designation indicates a specific firing schedule.

Look here for more information on Roseville Pottery marks.

Greg Myroth – Shop for Roseville Pottery