Qualitative Filter Paper - 2370-1850 - Grade 237, 18.50cmAhlstrom Munksj 237 3 m, Medium Speed This high absorbency grade is twice as thick as Grade 642 with similar particle retention. The superior absorbency offers excellent performance when used as a sample carrier. The extra thickness gives higher wet strength and loading capacity, enabling more precipitate to be held without clogging the filter. Grade 237 is also highly suitable for use in Buchner funnels and for dye filtration.