A sculptural seat with a pure and rationalist form, this chair became an authentic Manifesto for Neoplasticism, embraced by the Dutch De Stijl movement in 1917.‎ An outlook shared by Piet Mondrian, whose objective was to seek out the essential nature of things, combined with the harmonious equivalence of colours, and the use of right-angle.‎ Rietveld produced his first prototypes in 1918, expressing the philosophy of organising space using the same colours for similar components.‎ He later applied this same approach to separate out constructional elements according to their function.‎ Thus the base was black, and the seats coloured.‎ As a consequence, the name of the piece changed, from Slat Chair to Red and Blue.‎Seat/Backrest· Birch plywood panel with beech veneered edges and tops.‎Finishing polyester lacquer, halfpolished, in blue (seat) and red (backrest).‎Structure· Massive beech wood.‎ Finishing matt black lacquered, with crossbar edges in yellow or in white.‎The construction system of the frame of the chair is based exclusively on a sequence of joints and wooden pins.‎