Abstract: A method of preparing paper for filter bags, the method of the type comprising a step during which a non-woven paper is prepared comprising two superposed layers, namely a layer based on synthetic fibers and a layer of cellulose fibers, by a technique which is known per se, wherein the method includes a subsequent step of subjecting the non-woven paper to a calendering operation between a support structure and a heated cylinder having projections. The present invention also provides apparatus for implementing the method and products obtained in this manner.