Pin or nail the fabric onto a flat surface. Paint the muslin or linen surface with gesso -- a type of paint that stiffens the fabric so it resists wrinkling, similar to the texture of canvas.
Allow the gesso to dry for 24 hours.
Brush a solid layer of theatrical paint -- which is designed to reflect light for performances -- onto the fabric, for a solid backdrop known as a cyclorama. Allow it to dry, and then add a second coat.
Use light gray paint to transfer the design outline onto the canvas, for a background with scenery images. Apply colored paint after the scale and dimensions are depicted accurately. Paint darker colors in the foreground and lighter shades in the background, to convey the illusion of distance.
Sew a pipe pocket -- a cylindrical fold that holds a long piece of PVC or other pipe -- along the bottom of the backdrop. Use heavy-duty thread and the straight-stitch setting on a sewing machine, stitching about 1 1/4 inches away from the fold along the bottom.
Insert the length of pipe -- or multiple lengths, if needed for an extra-wide backdrop -- into the stitched fold pocket along the bottom. When your finished backdrop is suspended from the ceiling at the back of the stage, the pipe will help hold it in place and prevent wrinkling, providing a smooth surface for optimal light reflection.
Test the lights against the finished backdrop and adjust the lighting during rehearsal as necessary, until it appears balanced as it reflects from the backdrop and accentuates the performance.