While the Mirror Stack is often called a Stay-Stack, the latter is actually a principle applied to the Mirror Stack. Russell Duck (“Rusduck”) discovered that, if a deck in Mirror Stack is given a perfect faro shuffle, the mirroring element of the Mirror Stack is preserved. Duck published this discovery in the first issue of The Cardiste, Feb. 1957, “Rusduck 'Stay-Stack' System”, p. 12.