Extremely strong. It has a high wet strength due to the addition of a small quantity of chemically stable resin. Normal qualitative applications will not introduce any significant impurities into the filtrate. The resins do however contain nitrogen so this grade should not be used in Kjeldahl estimations etc. Ultra high loading capacity with a 30¬µm particle retention makes this filter ideal for use with coarse or gelatinous precipitates. It has the fastest flow rate of the qualitative grades and has a cr√™ped surface. This is the thickest filter paper in the qualitative range. Retention: 30¬µm. 100 circles/box.