Jameson Blender's Dog celebrates the craft of Billy Leighton, who is master blender at Jameson. This is a blend of both grain and pot still whiskeys that have been aged in ex-Bourbon and ex-Sherry barrels. Apparently three different spirit types are used in the grain and pot still element and four different barrel age profiles.
According to Irish Distillers this 'delivers butterscotch sweetness with a prickle of spice and tannins. Making whiskey requires a fair deal of science, but blending is an art.'