Volume is defined as an extension in three dimensions of a region of space. All bodies occupy a space that varies according to their proportions, and the measure of that space would be the volume. That is, volume is the amount of space occupied by an object or figure in three-dimensional space. The three dimensions would be length, height, and depth. Now, if we focus on the visual arts, the volume, as an element of visual expression, we can appreciate it in a real or figurative way.
Volume is an occupied space, but what we perceive of it is its shape. Through this shape, we experience the sensation of occupied space. In architecture, the volume would be the exterior set of a building, which encloses the interior space. There are two types of volumes: the solid, which refers to a mass that occupies a place in space, and the void, which is made up of several planes and contains space.
In the case of sculpture, we notice it when we are in front of this three-dimensional structure, that is, a sculptural object has a real volume, which has 3 dimensions, and with them, multiple points of vision. We can surround a sculpture, go through it, observe it from any of its angles, from the front, from the side, from above, etc.
If we move to the two-dimensional plane -let’s think of a drawing, a painting, or an engraving-, we will detect the simulated or figured volume. The volume in these cases would be the suggestion of three-dimensional characteristics that is achieved by strictly graphic elements. That is, if we properly combine the arrangement of resources such as points, lines, planes, textures, and color, we can visually imitate the volume of bodies. A line only has length, a plane has two dimensions, but if, for example, we take several planes joined together, in different directions, we can build a figure with volume, which simulates having height, length and width.
Given the need to represent nature as we see it, the notion of perspective was developed in the Renaissance. Perspective is a graphic representation, which is generally made on a flat surface (paper, canvas, etc.), of an object as it is perceived by our eyes, that is, it gives an idea of the position, scale, volume, and situation that the object occupies in space with respect to us, the observers. Bringing what we see, our perspective, to the plane, we create the visual illusion of depth.
How can we achieve the illusory effect of volume? Through the technique of modeling figures or chiaroscuro. This technique seeks to represent objects from the development and contrast of their lights and shadows. The darkest tones denote the maximum depth of an object, and the highlights reflect the direction of the light source that falls on it. The chiaroscuro then tries to give visual enhancement to the figure, seeking to recreate the volume in the plane.