Here are some examples of varieties found in Irish Stamps. To view varieties click on the description. The following abbreviations are used in the descriptions. "Scott" or "Sc" for " The Scott Standard Postage Stamp Catalogue", "MW" for The MacDonnell Whyte Stamps of Ireland Specialized Catalogue", and "Hib" for "The Hibernian Specialised Catalog"
Irish Varieties Thom third issue in Blue-Black, wide overprint
Line 1 - 12.5mm
Line 2 - 15.5mm
Line 3 - 3.5mm
Line 4 - 14.0mm
Line 5 - 6.75mm
Varieties in the overprint
The MW and Hibernian catalogs list a jet black overprint on the 1/2d variety as the only overprint variety for this issue, however, Hib indicates that the Plate 1 overprint can be distinguished from the plate 2 overprint by the difference in the "c" in "Sealadac" in position R20/1. The "c" has a straight base and long pointed end on plate 1, whereas plate 2 has a normal "c" in that position. That sounds like a variety to me and it is illustrated below with a normal for comparison.
