This invention relates generally to portable drawing surfaces and more particularly to a base structure with interchangeable components. The invention permits the manufacture of a base structure that can be combined with an accessory unit and a working surface to create either a lighted drawing surface or a drawing surface with a utensil accessory tray. Without this invention, it would be necessary to manufacture separate base structures to create drawing surfaces of different characteristics. For example, one manufacturing line would be needed for molding base structures for a drawing surface with a utensil accessory tray. An entirely separate line with another set of manufacturing equipment and operating personnel would be needed to mold base structures for a lighted drawing surface. Thus, a great deal of wasteful duplication in machinery and personnel would be necessary to make two distinct drawing surfaces.
This invention obviates the need for such duplicative efforts. The interchangeable nature of the base structure and other components enables the manufacture of multiple drawing surfaces with distinctive characteristics from the same base parts. This invention greatly reduces molding costs since molds for only one base structure, not two, are needed. This invention results in substantial savings in manufacturing costs as tooling requirements are substantially lowered. Thus, this invention permits the economical manufacture of portable drawing surfaces with either an accessory tray for storing drawing utensils or a backlit working surface.