The use of heraldic furs alongside the metals and colours dates to the beginning of the art. In this earliest period, there were only two furs, ermine and vair. Ermine represents the fur of the stoat, a type of weasel, in its white winter coat, when it is called an ermine. Vair represents the winter coat of the red squirrel, which is blue-grey above and white below. These furs were commonly used to line the cloaks and robes of the nobility. Both ermine and vair give the appearance of being a combination of metal and colour, but in heraldic convention they are considered a separate class of tincture that is neither metal nor colour. Over time, several variations of ermine and vair have appeared, together with three additional furs typically encountered in continental heraldry, known as "plumeté", "papelonné", and "kürsch", the origins of which are more mysterious, but which probably began as variations of vair.