A filter cartridge comprising: a pleated air filter media comprising a plurality of oppositely-facing pleats (20, 30) with a pleat direction and with a plurality of first-side pleat tips and first-side pleat valleys and second-side pleat tips and second-side pleat valleys, wherein the pleated filter media comprises a first major side and a second, oppositely-facing major side and first and second oppositely-facing non-corrugated ends (5, 5'), and third and fourth oppositely-facing corrugated ends (4, 4'); wherein the filter cartridge comprises a casing (50 with a first major portion that resides outwardly of the first major side of the filter media and includes a first air-permeable area, and with a second major portion that resides outwardly of the second major side of the filter media and that includes a second air-permeable area; wherein the casing also comprises a first end portion that resides outwardly of, and occludes, the first end of the filter media, and a second end portion that resides outwardly of, and occludes, the second end of the filter media; characterized in that the third, corrugated end of the filter media is occluded by a first edge seal of hardened adhesive that resides within the first-side pleat valleys and the second-side pleat valleys of the filter media at a location inwardly proximate the third, corrugated end of the filter media and extends along an entire lateral extent of the filter media, and wherein the fourth, corrugated end of the filter media is occluded by a second edge seal of hardened adhesive that resides within the first-side pleat valleys and the second-side pleat valleys of the filter media at a location inwardly proximate the fourth, corrugated end of the filter media and extends along the entire lateral end of the pleated filter media; and wherein the casing does not include any casing portion that resides outwardly of the third end of the filter media and does not include any casing portion that resides outwardly of the fourth end of the filter media. a pleated air filter media comprising a plurality of oppositely-facing pleats (20, 30) with a pleat direction and with a plurality of first-side pleat tips and first-side pleat valleys and second-side pleat tips and second-side pleat valleys, wherein the pleated filter media comprises a first major side and a second, oppositely-facing major side and first and second oppositely-facing non-corrugated ends (5, 5'), and third and fourth oppositely-facing corrugated ends (4, 4'); wherein the filter cartridge comprises a casing (50 with a first major portion that resides outwardly of the first major side of the filter media and includes a first air-permeable area, and with a second major portion that resides outwardly of the second major side of the filter media and that includes a second air-permeable area; wherein the casing also comprises a first end portion that resides outwardly of, and occludes, the first end of the filter media, and a second end portion that resides outwardly of, and occludes, the second end of the filter media; characterized in that the third, corrugated end of the filter media is occluded by a first edge seal of hardened adhesive that resides within the first-side pleat valleys and the second-side pleat valleys of the filter media at a location inwardly proximate the third, corrugated end of the filter media and extends along an entire lateral extent of the filter media, and wherein the fourth, corrugated end of the filter media is occluded by a second edge seal of hardened adhesive that resides within the first-side pleat valleys and the second-side pleat valleys of the filter media at a location inwardly proximate the fourth, corrugated end of the filter media and extends along the entire lateral end of the pleated filter media; and wherein the casing does not include any casing portion that resides outwardly of the third end of the filter media and does not include any casing portion that resides outwardly of the fourth end of the filter media. wherein the casing also comprises a first end portion that resides outwardly of, and occludes, the first end of the filter media, and a second end portion that resides outwardly of, and occludes, the second end of the filter media; characterized in that the third, corrugated end of the filter media is occluded by a first edge seal of hardened adhesive that resides within the first-side pleat valleys and the second-side pleat valleys of the filter media at a location inwardly proximate the third, corrugated end of the filter media and extends along an entire lateral extent of the filter media, and wherein the fourth, corrugated end of the filter media is occluded by a second edge seal of hardened adhesive that resides within the first-side pleat valleys and the second-side pleat valleys of the filter media at a location inwardly proximate the fourth, corrugated end of the filter media and extends along the entire lateral end of the pleated filter media; and wherein the casing does not include any casing portion that resides outwardly of the third end of the filter media and does not include any casing portion that resides outwardly of the fourth end of the filter media.