Monoprinting is a technique for creating a beautiful line on canvas and paper. It requires drawing on the back of the picture surface so that the line is pressed against an inked or painted surface. The resulting line is often very beautiful and quite unlike the link of line produced by a brush or a pen. It often picks up slight texture around the line which gives it a unique quality.
It is not a technique that is easy to use with canvas, the cloth must be quite thinly woven, and must be held at a slight distance from the painted board. I have never heard of it being used for a canvas as large as the ones planned for the hall ceiling, and so some experiments must be tried.