The process in which we separate out the insoluble particles from a liquid is called as filtration.we can use a filer paper or a filter cruicible for the filtration purpose.The filtration by filter paper is a slow process.In this process solvent passes through filter paper.

There are many types of filter paper which are available.They have different properties depending upon their difference pore sizes.We can choose a suitable filter paper.But its size should be large so that it should be ¼ to ½ full of preciphitates at the end of filtration.The funnel should be so large that its rim should be extended 1-2 cm above the filter paper.the stem of funnel in this process always should be long so that is can touch the side of the beaker .Stem of funnel during filtration remain full of liquid so that no air bubble produce in the liquid.we should fit the filter paper properly and a little bit tightly so that no any liquid could pass without filtration paper and in this way the insoluble particles are left behind on this filter paper.

There are many methods of folding a filter paper.Filter paper should be folded twice.the firs fold should be along the diameter.In Second fold the edges should not be quite matched.A folded filter paper should be opened on the larger section .Three fold sides and one fold side formed a cone.The angle of the funnel in which filter paper should be placed will always be .finally we wet the filter paper and then press firmly.Gentle section increases the rate of filtration.Fluted filter paper also increases the rate of filtration.

A fluted filter paper having many elevations and depression as compared to simple filter paper .we can fold a filter paper just as fan like arrangement with alternate depression and elevation gives a fluted filter paper.