A transflective display device has a well (30) formed in an insulating layer (20) for defining a dual-gap arrangement. At least one side wall (72) of the well is substantially perpendicular to the plane of the substrate and at least one side wall (70) is sloped away from the perpendicular to the plane of the substrate. In this way, some of the length of the well side wall is vertical, so that no pixel aperture is lost, and another part of the length of the side wall of the well is sloped so that good coverage can be obtained over that sloped side wall.