Signet, or 'seal' rings, are rings that incorporate a seal matrix used for sealing documents for authentication. From the thirteenth century, the growth in trade and written contracts led to a greater increase in the use of seals by members of the merchant and landowning groups. As these groups were generally not entitled to bear arms, they used instead such personalised motifs, or 'devices', as birds. Merchant's or guild marks were also used, as were the owner's initials.

Religious or magical inscriptions sometimes decorate the hoop. Here, the ring is inscribed 'God help William'.