The "Spot" whiskeys are named for the tradition of the old merchants, who used to mark different casks with a daub or "spot" of colored paint to mark them. Green Spot Irish whiskey considers itself a "pot still whiskey." We take this to mean that it is made in traditional pot stills in batches rather than the more common continuous column still with a blend of malted and unmalted barley (the commonly understood definition of Irish Pot Still whiskey--compare with "single malts" which are all malted barley). The brand has been around since 1925 (according to the write-up at Irish Whiskey Notes). The whiskey is made at Midleton (the same distillery that makes Jameson) but made exclusively for Mitchell & Son of Dublin, who has sole distribution rights. The story is an interesting one where the tradition of retailers bottling their own whiskey survives in the label of Green Spot. It is made in limited amounts each year (around 6,000 bottles) from whiskey aged 7 to 8 years in a marriage of traditional oak and sherry cask finish.
The Green Spot is also available in 10 year and 12 year expressions.