The group was given its conventional name by John D. Beazley during his studies of Attic red-figure was painting.
He named the group "YZ" because he recognised their work as the latest known figural red-figure paintings.
The exact date of the end of red-figure painting remains unclear, because no detailed chronology can be developed from the vases.
The fact that YZ vases are relatively numerous may indicate that their production, though short in duration, was large in output.
The tondos of bowls resemble works from the early 4th century, but are more casual and coarse in execution.