Never heard of the term crazing? Well, it is relatively new to me, too. I found out about it by trying to find out why some of my favorite antique serving pieces had webs of cracks in them. In fact, it seems like every time I use them, the networks of cracks spread. Case in point: my Homer Laughlin oval platter. A few pieces now have discoloration (like my round platter) to boot. What gives? Turns out that crazing (not to be confused with crackling, which is an intentional crazed glaze effect) can occur due to a number of reasons, including defects in the glaze, prolonged exposure to water or moisture, being jostled or moved a lot, or just plain old age. The discoloration is a result of moisture and organic matter like food (or even dust particles) that can turn into bacteria that stains the pottery. Does crazing devalue the item? Well, it is not great but cracks and chips are worse. Plus, people like me often love the effects of gentle crazing because it adds an old-fashioned patina of texture and age — especially to old white pottery and porcelain. As is often the case with collectibles, the value is in the eye of the buyer!
Bonus trivia: the way to decipher the date code on the back of the Homer Laughlin platter is: the L represents December (L is the twelfth letter in the alphabet and December is the twelfth month.) The 5 represents the year 1925. The N means that it was made in their plant in Newell, West Virginia (in December of 1925!) If only I knew the name of the pattern. Please comment if you do!