Before an artist or craftsman can render a Coat of Arms, it must exist. In other words the arms must have been designed and recorded by heralds.
Heraldic designs researched by the lay-artist are in many cases inaccurate and portrayed incorrectly. However, to the Heraldic Artist the same design presents a formidable challenge, whilst he/she may enjoy considerable freedom within certain limits. The objects in the arms, crest and supporters, their colors and positions may not be altered, but how each object is rendered provides a wide latitude of design to the artist.
Thus, a Lion Rampant, Gules armed and langued, Azure, can be fat, thin, hairy or bald, happy or angry, but it must be in the rampant position, colored red and the tongue and claws of blue. Beyond these limits the artist is free, to choose the shape of the shield, style of helm (befitting the rank) and to arrange the mantling to create a well balanced composite design.
Traditional rendering of objects in heraldry are for the most part closely observed, regardless of the modern scientific knowledge. Thus a dolphin is rendered as a fish as it was up until the mid 20th century. The martlet is another example of the heraldic artist's faithful following to historical designs. Martlets are always depicted without feet. They were a fairly common bird that followed ships much like the seagull of today and because it seemed that they never landed, people thought they had no feet.
- ^ Swyrich, Archive materials