A suppressor for use in reducing a background signal while detecting analytes in a liquid sample for ion chromatography is described. The suppressor includes a central channel and two flanking regenerant channels. The central channel is formed with an eluent channel plate including a central cutout portion having a peripheral boundary portion. The peripheral boundary portion includes a recessed eluent plate height that is less than the eluent plate height. The peripheral boundary portion includes two or more notches or protrusions. An eluent screen is disposed in the central cutout portion, in which a peripheral border of the eluent screen has two or more corresponding notches or corresponding protrusions to the eluent channel plate.