Scratchboards are specially prepared art boards where paper is mounted on wood, then covered with a white clay and a black ink. Drawings are made by taking a special scratching tool (actually an Xacto knife blade works well) an removing the black ink to reveal the white clay beneath. Sometimes abstract designs are created, but excellent detailed and realistic images are also possible. Student-grade scratchboards are available at art stores, but serious artists often use high-quality products imported from England. Despite the subtractive process, wonderful positive images are created by this method.
Monotyping is a printmaking process where a glass plate is first covered with black ink (any color ink can be used). While the ink is still wet, an image or design is made on the plate by scraping or scratching away part of the black surface. Then the ink is transferred by means of a press to piece of white paper to create the final picture or design. Each plate or piece of glass will produce one final image, hence the name monotype. Keep in mind that the process described above is only one of many ways to create a monotype. Still, the use of a black ink surface is a challenging way to begin printmaking.
If you are familiar with soft pastels, you probably already know about the black-colored pastel paper that is available at most art supply stores. You can use this paper as a background for both soft pastels and oil pastels, as well as an opaque water-based paint such as acrylic or gouache. A good beginning project would be to set up a still life and then go about making a drawing of the setup with sticks of soft or oil pastels. You will need to do several drawings to get the feel of the combination of dark paper and the stick medium, but this exercise should provide valuable experience in working with a dark background and learning how to build form and shape with these materials.