Qualitative Filter Paper is available in three standard grades.

• Applicable to Most Science Education Applications
• Grades One, Two, and Three Available
• Grade One Works with Routine Applications
• Grade Two Filters Large Samples
• Grade Three Works with Buchner Funnels

Grade One filter papers are mainly used for routine applications such as separation of precipitates and filtering liquids. They have medium retention and flow rates. Grade Two filter papers are more retentive and absorbent than Grade One papers. Usually, Grade Two filter papers have an 8 µm particle size range and are used for filtering larger sample types such as soil.

Grade Three filter papers are approximately double the thickness of Grade One filter paper, which makes them more durable and suitable for use with Buchner funnels.