Draw your shape on plastic transparency film and use a razor knife to cut the template. Precut plastic templates found in craft stores work well too.
Lay the film over the paper & lightly apply a tooth brush to the surface to remove the paint.
Quickly blot the paper with a paper towel to remove the excess water.
The template lightens the painted area in the desired template shape. Additional detail lines can be gently scrapes away with a razor knife.
The amount of paint that can be lifted depends on the type of paper as well as the staining quality of the paint. Soft papers such as Lana can be restored to almost the white of the page.
NOTE: Once an area has been lifted it will absorb any future paint applications. Avoid scrubbing the paper too harshly - this can cause the paper to pill.
In the painting, "Beach Promenade" a template was used to create the bird shapes in the sky. The sand was textured with the use of salt and the sand dunes were created with saran wrap.