Hawach Scientific Co., Ltd qualitative filter paper is divided into standard grade and wet strength grade. The wet strength grade adds a small amount of chemical stabilizer to the standard grade. Wet strengthened grades are with better moisture resistance. The ash content of qualitative filter paper is less than 0.1%. Qualitative filter paper covers a wide range of laboratory applications and frequently used for clarifying liquids. Wet Strengthened grade filter paper exhibits excellent compression resistance under high pressure and vacuum laboratory conditions and is not easily damaged.