The flow of molten metal through ceramic filter media depends upon many variables such as pore size, pore shape, pressure difference, metal viscosity and others. In the Investment Casting process a common method of using ceramic filters is in the pouring cups where inclusion removal and turbulence reduction are beneficial. This method, while convenient, can seal off the top of the pouring cup. Unless other venting is provided, gas in the mold must now either escape through the shell due to its permeability or bubble upstream back through the filter. This can lead to a pronounced slowdown in the rate at which metal can pass through the filter, leading to cold shuts, misrun and non fill. An easy to employ method is presented where the pouring rate can be maintained throughout the pour, alleviating the tendency of cup mounted filters to increase the occurrence of these defects.