Grade 4V Folded Filter Paper, Circle 18.5cm. A prepleated filter paper widely used for general purpose filtration. Has excellent particle retention and a good filtration speed and loading capacity. Savings in time required to quadrant-fold circles to fit conical filter funnels in repetitive or multiple analyses. Decreased overall filtration time because of the extra surface area exposed; the normal slow down of filtration speed due to the loading of particulate is postponed. Increased total loading capacity as more filter area is available. Maintained flow rate due to the reduction in filter paper contact with funnel side and the self-supporting shape of the filter itself. The prepleating does not significantly affect any of the technical data, and the same figures may be used for the flat circles.