While there were many horse whittlers in the early production of Dala horses, there were comparatively few horse painters. The large number of whittlers and a lack of distinguishing features makes it difficult to distinguish between different whittlers. Early painters very rarely signed their work, but they did have their own distinct pattern from which it is often possible to identify who painted a particular horse. In the 1930s (especially after the World's Expo in Paris 1937 and World's Fair in New York 1939 in which Dala horses were shown) mass production of Dala horses started. This marks the beginning of a new era for the Dala horse, transitioning from toy to a national symbol and popular souvenir.