You create a hatch by selecting an object to hatch or by defining a boundary and then specifying an internal point. A hatch boundary can be any combination of lines, arcs, circles, polylines, ellipses, blocks, and paper space viewports that forms an enclosed area. You can also specify points to define a boundary. If you are hatching a small area in a complex drawing, you can use boundary sets to speed the process. Each boundary component must be at least partly within the current view.
You can hatch islands within the boundary or leave them unhatched.
Objects can be hatched only if they are in a plane parallel to the current UCS. The interiors of polylines with width and solid fills cannot be hatched because their outlines are not acceptable boundaries.
Using Boundary Sets
Specifying Points to Define a Hatch Boundary
Controlling How Islands Are Hatched