In the rigorous taxonomy of British armory, Vair is classified as one of the two principal furs, alongside Ermine. It traditionally depicts the winter pelts of the grey squirrel (Sciurus vulgaris), which were sewn together to line the ceremonial robes of high-ranking nobility and royalty. In its stylized heraldic form, the fur is represented as several rows of alternating bell-shaped or 'shield-shaped' segments, aligned so that the bases of the blue patches meet the bases of the silver patches, creating a distinct tessellated pattern of 'pates' and 'points'.
Scholarly distinction is made between the standard Vair and its various permutations, such as Counter-Vair, Vair-en-point, and Potent. While the standard form utilizes Argent (silver/white) and Azure (blue), any variation in coloration is blazoned as 'Vairy' of those specific tinctures. Historically, the presence of Vair on a shield denoted significant status and wealth, reflecting the literal luxury of the fur linings used in the courts of the Plantagenet and Capetian dynasties. During the development of the classical roll of arms, the scale of the pattern (the number of rows) often indicated the chronological era of the grant, with fewer, larger rows appearing in earlier medieval examples.