Some wineries display a "library" of their vintages—e.g., a Stag's Leap Petite Sirah from 1990 to 1994— in their tasting room to show guests how their wines have evolved and (hopefully) matured from year to year. Usually these library wines are sold only at the winery, but occasionally a winery will market a particular varietal as a library wine, such as Château Souverain's Cabernet Sauvignon Library Selection.