Filter Paper Qualitative Slow 5 cm. 100 Filter Circles. Excellent Quality. Ash Content 0.15%. Fast "Creped". Retention: Coarse, Gelatinous, Precipitates. Filter Paper grades have varying particle retention and flow speeds. Fast Papers will retain larger sized particles and Slow Papers will retain smaller sized particles. The ideal choice is a Filter Paper that is fast, and able to retain the precipitate load. Box of 100 papers.