The Irish Mythology definitive set was released during the summer of 1994. four cards, depicting paintings by artist Pauline Bewick make up the set.
Different variations do exist, due to multiple chipset manufacturers producing each card. As the definitive cards would have had multiple print runs, some even minor differences can also be noticed (colour tones for example).
Note: Piero Tintori suggests in The Concise Irish Callcards Catalogue that an ODS1 chipset variant for Deirdre of the Sorrows exists. This is not believed to be true.