Masks can be used in painting to create unique textures, patterns, and effects. Here are some techniques:

1. Stenciling: Use a mask as a stencil to apply paint in specific shapes or designs.
2. Resist: Apply paint over a mask, then remove the mask to reveal a resist pattern.
3. Texture: Use a mask to create textured surfaces by applying paint or medium through the mask.
4. Pattern making: Use a mask to create repeating patterns or designs on your canvas.
5. Layering: Use masks to build up layers of paint and create intricate, layered designs.

Some popular types of masks used in painting include:

- Stencil masks
- Tape masks
- Paper masks
- Gel masks
- Stencils with intricate designs or patterns