Always hang unbacked fabrics. Such as hessian or decorative felt. On a surface that has been lined – never on a bare surface. Then apply the recommended adhesive to the lining paper, and not to the fabric, when hanging it. This prevents stretching and avoids the danger of overlapped edges soiling the fabric underneath. Overlap the edges by 25mm. And when the adhesive has partially dried make a butt joint by cutting along a straight-edge through both pieces of fabric down the centre of the overlap.