Back drops that either roll or lift up from the stage make your theatrical scenery more flexible. You can store a castle, the whole city of New York and a Cruise Liner the size of the titanic, on painted back drops, in just a few feet along the back of your stage. Since fireproofing and grommets are required, all but the largest professional theatres order the actual fabric panel from a supplier. They will send you a back dust sheet designed to the specific size of your stage that can then be drawn and painted on to create the scene.
Stretch your back drop out and lay it flat on the stage with the top edge, containing grommets and ties, toward the back of the stage. Release the batten, or hanging pipe, for the back drop from its locked position and lower it down to about three or four feet above the stage.
Start with the middle grommet and tie and find the centre of the pipe, or batten, which is typically marked with a C with a vertical line running through it, much like a "cents" sign. Tie the middle tie to the pipe with a shoe string bow knot. Pull out from there, tying the next string to the pipe on either side. Continue down the pipe, tying all of the strings to the pipe.
Raise the batten and slip a pipe into the bottom pocket of the drop, most theatres have several lying around for this purpose, if not, use chain link fence top rail. Shift the pipe into the pocket slowly to weight the drop and stretch the fabric.
Use an opaque projector to project the image you want to portray onto your backdrop. Use a photo, a picture of another backdrop or something you draw. Dim the lights in the theatre to make it as dark as possible. Trace the outlines from the projection onto the drop with wide pieces of sidewalk chalk in a colour such as grey, or blue for easy visibility.
Lay heavy plastic dust sheets across the stage. Let the batten back down and untie it. Leave the pipe in the bottom and stretch the backdrop out on your stage. Take off your shoes and make sure your socks are clean. Step onto the back drop and start from the centre using latex paint mixed 1 part paint, to 1 part water with a long handled paintbrush to block in the colours of the scene. Continue working from the middle out, until all of the colours are blocked in.
Allow the paint to dry completely. Mix some of each colour in two separate containers with a little white for a highlight and a little black for shadow. Use a wide art brush to paint shadows along the bottom edges and the side that is away from the light source, as you imagine it, in your painting. If the sun is left and above, shadow on right and below. Paint highlights on the opposite side of every shape.
Mix a dark grey colour and add water until it is the consistency of dark coffee. Use a 2 to 3 inch wide brush, with dry bristles. Dip the brush into the thinned paint, about 1/2 inch. Snap the brush toward the canvas with a flick of the wrist to sprinkle paint drops onto the back drop. Do the same with white. Sprinkle the drops across the whole back drop lightly, to "spatter" it, giving it a little more feeling of "depth".
Allow the drop to dry before retying it to the batten and lifting it up into position.