"Sailors' woolworks, commonly known as ‘woolies’ or string pictures, ship pictures, embroidered ships, sewn ship pictures, or silkies, were produced from around 1840 until they fell out of fashion around World War I; many men passed the long hours on board, as well as kept their fingers nimble in the wind and cold, by sewing scenes of their ships and landscapes. As woolies or woolworks are often unsigned, the names of the artists are largely unknown.

Primarily, woolies depict ships, but many contain other elements, such as patriotic symbols, flags, or landscapes.

While it is regarded as unusual for men to have had this particular hobby for making woolwork or string pictures, it is actually not so strange; until the 1880’s, seamen had no standard uniform and had to provide and maintain their own. Another task they faced was repair of the sails – coupled with the need to mend their own clothing, the sailors had to have at least a rudimentary knowledge of sewing."

https://www.sothebys.com/en/buy/auction/2021/important-americana/sailors-woolwork-picture-a-woolie-of-a-royal-navy