Selected Bibliography Architectural Graphics | Page 139

TONAL VALUES & TEXTURE We use the term "texture" most often to describe the relative smoothness or roughness of a surface. It can also describe the cha racteristic surface qualities of familiar materials, as the hewn appearance of stone, the grain of wood, and the weave of afabric. This is tactile texture that can be felt by touch. J Our senses of sight and touch are closely intertwined. As our eyes read the visua l texture of a surface, we often respond to its apparent tactile quality without actually touching it. We base these physical reactions on the textural qualities of similar materials we have experienced in the past. • Whenever we use hatching or stippling to create atonal value, we simultaneously create visual texture. ~I !' II ]I II l I ~ -it j I [ 'I '[ II II !I l' I ' I I i t- II I, 0/ II ll~ \ D (~\1 A /J • Likewise, as soon as we begin to describe the nature of amaterial with lines, we simultaneously create atonal value. A\ • We should always be aware of t his relationship u between tonal value and texture, whether smooth or rough, hard or soft, polished or dull. In most cases, tonal va lue is more critical than texture to the representation of light, shade, and the way they model forms in space. RENDERIN GT ONAL VALUES/ 133