A ground cover sheet material (1) woven from warp and weft tapes is disclosed. The material comprises regions of relatively thicker warp tapes (11) and regions of relatively thinner warp tapes. The thicker regions are at or adjacent one or both longitudinally extending opposite side margins of the material, and one or more longitudinally extending centre regions near or adjacent a notional centre (30) or fold line of the material. The thinner regions make up the balance of the sheet material. By employing one or more thicker warp tape regions the centre of the sheet, the material can be rolled up more evenly to maintain a more even tension across the entire warp during the manufacturing process than if the thicker warp tapes were only on the side margin(s).
