Abstract: A grid which produces a vaultlike appearance on one side comprises a first series of parallel plates extending in one direction and a second series of parallel plates extending in the direction to intersect the first series of plates. At least one of the series of plates is generally concave on the one side; when only one series of plates is generally concave on the one side a tunnel effect is produced with the side edges generally concave, but when both series of plates are generally concave on the one side, a dome appearance is produced. The grid may be used as a ceiling grid and illuminated, if desired, or as an upright partition or divider placed on one edge. The opposite edges of the plates may be equidistant, including any deviations from a curve on which the edges may be laid out. A series of scallops, concave on the one side and convex on the opposite side of each plate may have the length corresponding to the distance between intersecting plates.