As a chemistry student, I was always taught to flute my filter papers, but a heated debate about another method of using your filter paper is raging on the Chemed-l discussion group about why others fold their paper and then tear off the corner. Hal Harris University of Missouri-St. Louis reckons the little corner tear improves the filtering process and also speeds it up significantly. So much so, he says, that “Over a lifetime in chemistry, I’m sure that this has saved me a cumulative 20 msec, at least.”
Meanwhile, here’s the standard method of fluting filter paper. The technique is used when you wish to separate a liquid and a solid, keeping the liquid and discarding the solid. The specific arrangement of folds (flutes) in the filter paper will allow the liquid to pass through it very quickly and at the same time provide a large surface area on which to collect the solid impurities.