Shape is another basic element of design. A shape is any two-dimensional area that can be defined by its boundaries. One way we better understand line is by how it defines the boundaries of a shape. Often a shape is identified through contrast - how it differs from the other area around it. It might be a different color, a different value, or a different texture. A shape can be organic or geometric. A shape can be considered an aspect of the positive space or one of the negative space. If that shape suggests three dimension, then it is more rightly perceived as a mass. In a painting this is referred to as implied weight as the mass does really exist - other than being paint and canvas.