Devising rigid bent elements that could simultaneously serve as leg and support for a seat was the object of considerable research by Alvar Aalto. He called the standard leg of his three-legged stools the 'Doric' leg or the 'bent knee'. Aalto and Otto Korhonen patented (in Scandinavia and Britain) the method by which the Doric legs were formed: thin sawcuts were made along the grain of a piece of birch wood (most of the length of which formed the leg), thereby allowing the necessary flexibility to bend the piece at the top. Into these slots were glued thin sheets of veneer, which, when set, maintained the right-angle bend. At first, the L-shaped legs had to be manufactured by hand, forming the tight curve out of the separate veneers of wood as it was glued, but a machine was soon developed that could perform this action in a hot press. The stool is reduced to its basic industrial components: an L-shaped leg and a circular top. Dozens of stools could be stacked in a corner, and the resultant spiralling form became a motif of displays of Aalto furniture in the 1930s and ever since.

Many thousands of these stacking stools were produced. They were used in quantity in the Vipuri Library, which was built and furnished between 1930 and 1935. The original stools had the traditional three legs, which avoid any rocking on an uneven surface. Four-legged stools were manufactured by special request from 1935. The basic bent leg is a classic development of Modernist thinking without the hard and cold qualities of metal construction. In modified form the three-legged stools are still produced today in huge quantities, meeting the basic need of robust additional seating.