Abstract: A filter cartridge or element for separating particles from fluid flowing inwardly through the cartridge, and a process for making the same, such cartridge having a central perforated inner tubular core member with a pre-formed mat of non-woven fibrous filter material having a width substantially equal to the length of the core member and wrapped around only the core member and itself in a continuous spiral layer to form a roll of the mat. The roll mat of filter material is contained or confined by an open mesh material such as that formed by a substantially single layer of a strand of roving wound in an open criss-cross or open diamond weave pattern around only the outer periphery of the material of the rolled mat and itself so as to maintain a permanent dimensional and structural stability or integrity during subsequent handling and use.