For appearance properties, one must use apparatus which measures physically those optical characteristics of paper to which the eye responds. For color and whiteness, spectral accuracy is important. For gloss and transparency, the geometric design of the measuring apparatus receives major attention. The present study is divided into parts dealing with (1) the physics of appearance, (2) its division into spectral and geometric attributes, (3) color, (4) gloss, and finally (5) some work we've been doing on whiteness.