An encounter with the words monopigments or polymeric pigments leads one to wonder what they mean exactly. Tannins are divided into two basic groups, namely the flavonoids and the non-flavonoids. The non-flavonoids consist of gallic acid, ellagic acid, hydroxycinnamic acid and hydroxybenzoic acid and their derivatives. Flavonoids consist of flavonols, flavan-3-ols, flavan-3,4-ols and anthocyanins.