Abstract: A spray booth installation has a water tank 10 from which water is withdrawn by a pump 11 to feed a water curtain covering a wall located above a dividing baffle plate 17 in the tank and to feed sprays in an air extraction passage disposed above a region 16 of the tank. A surface-removal device 20 including a venturi pump keeps the water surface clear of paint in the vicinity of the pump inlet 13 and ejects the floating paint on the other side of the baffle plate 17. A surface baffle 30 retains floating material while allowing water to circulate back to the front region 15.