Mat Extensions: When the image to be framed suggests an extension, I paint the mat with great care, not wanting to damage the item being framed. I use mostly gouache and watercolors but do no rule out the use of acrylic and pastels when I need their effects. Even pencil crayons and carbon pencils have their uses. All images I frame for my gallery walls have a special treatment, but not always in an extension. I strive to have the entire framing become an art piece.