First of all, hold in mind that “EPIAG” is not a single factory but a consortium. The different members of the group marked in a specific way as they all used parts of their former main marks combined with the EPIAG brand.
In your case, the mark shows that the item was made at the factory of the brothers [i]Oscar & Edgar Gutherz[/i] in the town of [i]Altrohlau[/i]. As the addition reads “Czechoslovakia” (without a hyphen or C-Hatschek character) it was not used earlier than 1921; it remained in use until 1938 (Parts of Bohemia were occupied by Germany a year before the invasion of Poland).
I have an entry on the background of the OEPIAG / EPIAG here:
[url=”http://www.porcelainmarksandmore.com/related/bohemia/altrohlau-00/index.php”]http://www.porcelainmarksandmore.com/related/bohemia/altrohlau-00/index.php[/url]