Archaeological finds suggest that the Vikings´ sails were mainly made from wool. Norwegian poetry from the 11thcentury and 13th century written sources also mentions this.
In the Oseberg find (ship dated to AD 820) and Gokstad (AD 895) large quantities of thick woollen material were discovered, impregnated with tallow or fat and dyed in red ochre. The thickness of the materials suggests that these were remains of sails.
Could other materials have been used? Conditions of nature and access to resources likely played a decisive role in selecting materials. Written sources from the British Isles mention both wool and hemp. The ship known as Skuldelev 2 found in Denmark (but built in Ireland in AD 1042) might have had sails made from hemp. The sail was crucial for the Vikings´ expansion and trade.