Completed Ebay auctions are the best source of information about the current, real world, value of antiques and collectibles. However, determining accurate values takes some effort.
When I was researching this post there were 56 items listed for a search of "Westerwald". Some of these were postcards with pictures of the Westerwald region of Germany. Eliminating those still left a wide variety of items that were alleged to be Westerwald stoneware. It's obvious many sellers know little or nothing about what they are selling. They use words in the title they think will attract buyers without much concern for accuracy or appropriateness. If you plan to use the results of their sales to identify and value your own pieces, you will need to do some careful research.
The words "Westerwald Stoneware", "Westerwald Pottery", "Salt Glaze", "Stoneware", and "Cone 10" all get used in imprecise ways because sellers don't really know what they mean. We bought some Westerwald stoneware from a seller in Germany and my notions of what it should look like are based on those pieces. It turns out we do not have a representative sample so my ideas needed to change.
To begin your education about Westerwald stoneware keep in mind that salt glazed earthenware with cobalt blue decoration was made in Germany starting in the 1400's. It was both imported to and made locally in New England, USA as early as the 1600's.
Much of it was what might be called Utilityware. It was made to be used to hold products such as fermenting cabbage (Sauerkraut). These pieces had minimal decoration. They were made to be cheap and functional. No one bothered much about makers marks or logos on this cheap stuff, so it can be very hard to tell much about origin and age just by looking at these pieces.
Some of it was crafted as Displayware. These pieces had assorted designs scribed onto them. Many have a three dimensional aspect with grapes and other design motifs raised above the surface of the vessel. They were decorated with Cobalt Blue glaze in artistic ways. With the grey background and the bright blue highlights these vessels look very nice when displayed in a natural wood cabinet.
