Self-sealing liquid filter

A liquid filter for filtering particles from a liquid said filter comprising a pleated filter material having upstream and downstream pleat tips each pair of upstream and downstream pleat tips being separated by a planar pleat section of the filter material, where the filter material has upstream faces and downstream faces, the upstream pleat tips forming an upstream face of the filter and the downstream pleat tips forming a downstream face of the filter where at least on the downstream face of the filter there is provided a rigid porous support structure, the upstream and downstream faces of the filter material on mutually abutting pairs of planar pleat sections between adjacent upstream and downstream pleat tips are separated by 6 mm or less on average, the downstream face of the filter being in substantially continuous contact with a porous self-sealing fibrous cover layer which self-sealing fibrous cover layer is coplanar with and in substantially continuous contact with the rigid porous support structure and which self-sealing fibrous cover layer performs essentially no filtering function.