During the 11th century, professional runemasters (most from eastern Svealand) were contracted to make runestones which they sometimes signed, but many uncovered runic inscriptions were completed by non-professional runecarvers.
During the 11th century, when most runestones were raised, there were a few professional runemasters. They and their apprentices were contracted to make runestones and when the work was finished, they sometimes signed the stone with the name of the runemaster. Many of the uncovered runic inscriptions have likely been completed by non-professional runecarvers for the practical purposes of burial rites or record-keeping. 
