Shade Charting: Can we take perfect shades every time? Imagine you have a hot dog covered in mustard on a bun. Close your eyes and imagine what it looks like. What color is the mustard you envision? Is it vividly bright yellow like French's, or is it Gulden's or Grey Poupon or some other brownish-yellow brand of mustard? Both are yellow mustards in the broadest sense - but they are very different in appearance aren't they? In dentistry, how can we effectively communicate color? If you're charting a shade on a patient, and you cannot find a shade tab to match a natural tooth, (number #8 for example) - but you see a yellow dominent hue at the cervival,  which one of the many yellows will you ask the ceramist to include in the replication? Honey yellow?..banana?..perhaps a blend of a yellowish-ochre? Maybe the color you see is mustard yellow! But will your ceramist envision the same brand of mustard? You can see where we're heading. We need to be on the same page. Look at an orange. You think you're seeing the orange directly, but you aren't. What you see when you look at any object is light reflected from the object and transduced into an image in your brain. An orange peel will not look the same in the morning sun as it will in the artificial light of your kitchen in the evening - nor will it look the same if you shine a spotlight upon it, or when you view it at dusk as natural light fades. If you place the orange on a blue tablecloth, it will look different than on a white one, and as light sources change, the intensity of the colors will also. Color is a marvelous phenomonon, but absent from light - the world would be without color. Light allows us to "see" all the colors of the spectrum. Certainly, it is the primary factor in selecting shades in human dentition. Always consider the light source(s) when selecting shades. The angle of the light, the type, the intensity, are all factors that can & will change.   In order to replicate teeth as naturally as possible, first  determine the value within a given range of hues. Re-check the value with the patient standing, and if possible, in two or more light sources. Finally, re-check the value again.  It can be decreased, but it can never be raised once the porcelain is furnace-matured.