Decide what kind of veil you are going to sew - in two parts. monolithic, with elastic or without. Monolithic blanket for such a large sofa is quite difficult to sew, so it is best to make separate covers-covers for each part of the sofa. For a solid bedspreads you need to connect two components at an angle of 45 degrees. Also the perfect solution elastic band, stitched at the edge of the curtain case, in which case they will not slide.
Carefully obmerte part of the sofa that you want to conceal, draw the pattern on graph paper (in reduced form). When making patterns do not forget about the allowances somewhere 1.5-2 cm.
Cutting your chosen fabric according to the dimensions in the pattern.
Sew a connecting seam of the paintings, then make a neat hem and the edges of the curtain, if desired, insert the rubber band. Carefully iron the finished product with steam.
The veil on a corner sofa a good idea, especially in cases when the sofa is not disassembled at night. If you use the sofa as a permanent sleeping place, possibly in this case, the solution would be a blanket or a fur pelt.