condensation from a glass, can easily be treated with clean water. In this case, a stain results because water has dried in the middle of a piece of leather, leaving a clear line of separation. Wet the entire area out to a seam or edge. Soak a new sponge in a bowl of room temperature water. Wring it as dry as possible. Start at the spot of the water stain, dampening the leather until you reach the edges of the cushion. Wet the leather less and less as you get further from the water spot. Do not scrub, just wipe. Condition the leather after it has dried. Other liquid stains can be treated in the same manner, but may require professional treatment.