Qualitative filter papers are recommended for use in analytical methods which determine or identify particular constitutes of a mixture regardless of the amount present. They are often used in routine separation work that still requires high purity and consistent performance.
Standard qualitative filter papers are suitable for quadrant folded or gravity flow applications. They are cellulose based providing high purity but will weaken when wet. The inherent stregth of the standard grades does not pose a problem when they are used in routine quadrant folded applications.