For Leather: For a proper preparation apply the Tarrago preparer scrubbing if necessary with a "used scotch brite pad" to remove any dirt, shoe cream or protector that may prevent a correct application of the dye.
Synthethic leather: DO NOT use the scouring pad but rub with a cloth soaked in Tarrago Preparer to remove dirt of shoe cream or protector.
Canvas: Wash shoes with water or mild soap.