A panel 1 comprises a frame 2 having first and second frame portions 2a, 2b each provided with a longitudinal channel 7. The panel also comprises sheet material 4 extending across the frame 2 between the frame portions 2a, 2b. A first edge portion of the sheet material is inserted into the channel of the first frame portion 2a and a second edge portion of the sheet material is inserted into the channel of the second frame portion 2b. The first edge portion of the sheet material has a region of stiffened edging 6 that is located within the channel 7 of the first frame portion 2a. The second edge portion of the sheet material 4 is gripped within a resilient slot formed by a gripper member 5 that provides at least one resilient gripper element 5b in the channel 7 of the second frame portion 2b.