The glass requires regular cleaning with special products intended for this purpose. The special product must be applied using a soft cloth and not directly onto the glass. JC BORDELET fireplaces have been designed to reduce the soiling of windows as far as possible. Using high quality wood will also help keep soiling to a minimum. The fireplaces have been designed to make cleaning of the windows (swinging or sliding) easier, depending on the shape and model of your chosen designer stove or fireplace.