Good day Alan- have you and your compatriots decided on the best metal add-on filter? Copper? Go Stanford! (and Go Berkeley!) – From Hugh O.

Paper filters are the only way to remove two harmful chemicals in coffee. They are cafestol and kahweol and they raise LDL cholesterol. You can read about this by Googling 'coffee cholesterol'. We also did blind taste test comparisons between coffee brewed using a metal filter and coffee brewed using a paper filter and the paper filtered coffee always won. This is why we only sell paper filters for the AeroPress.