Non-compact stencil

Imagine you have a coloring book page, and you want to paint it using a paintbrush. But this paintbrush isn't like a regular paintbrush - it has a special shape that lets you paint in a certain pattern. This shape is called a stencil.

Now, a regular stencil would be like a square or a circle - it has a fixed shape and size that you can paint within. But a non-compact stencil is different - it can be any shape or size, and it doesn't have fixed boundaries.

For example, imagine you're painting a picture of a tree. The non-compact stencil would be the shape of the tree itself - the branches, leaves, trunk, and so on. With this stencil, you can paint within the boundaries of the tree shape, but you can also extend the edges or create new sections to make the tree look more realistic.

The advantage of using a non-compact stencil is that it gives you more freedom and flexibility when you're creating your painting. You can adjust the size and shape of the stencil to fit your needs, and you can add more detail or complexity to your painting by extending the edges or creating new sections.

In summary, a non-compact stencil is a special shape that lets you paint in a certain pattern, but it doesn't have fixed boundaries like a regular stencil. This gives you more freedom and flexibility when you're creating your painting.