A standard grade filter paper for fine precipitates .

• Maintains flow rate due to the reduction in filter paper contact with funnel side and the self-supporting shape of the filter itself.
• 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.
• Savings in time required to quadrant-fold circles to fit conical filter funnels in repetitive or multiple analyses.
• Increased total loading capacity as more filter area is available.
• The prepleating does not significantly affect any of the technical data, and the same figures may be used for the flat circles.