Quaich, cuaich in Gaelic meaning "cup", are a uniquely Scottish invention. Having no apparent connection to any other European drinking vessel they have maintained their distinctive shape as a wide and shallow cup for more than four hundred years. There are some scholars who believe the shape evolved from the use of scallop shells.
The earliest written reference to quaichs is from 1546 and by that time they were already long established in Scottish culture. In a time when people didn't drink out of someone else's cup, the quaich was used ceremoniously at weddings to indicate the couple were "quaffing" together - trusted other enough to drink from the same cup. At christenings, a quaich was often given to the baby if a boy, or handed around and ceremoniously drunk from to indicate all in the room were trusted friends.
Travellers were known to carry a quaich with them, hanging it from their belt or saddle and used it to drink from springs, in taverns and inns. The cups were the equivalent of one finger, two fingers, three fingers... along the way they became a standard measure for whisky, one finger (deep) being the equivalent of a contemporary dram or one eighth of an ounce.
A quaich was traditionally made of wood by alternating a dozen or more staves of light and dark wood (such as plane-tree and laburnum) like a sunburst, tangentially or were "feathered" together and then bound with withies (strips of willow) or silver bands. A pair of handles, called "lugs", extended horizontally from the rim and these were often covered with silver. The centre of the bowl was usually decorated with a silver coin or an engraved disc or 'print', with coat-of-arms, initials, motto or familiar phrase such as a toast. The disc served the function of masking and sealing the centre of the bowl where the points of the staves met.
Slainte Mhath, "to your very good health", or Sguab as e, "polish it off".