English bone china can be identified quickly in one of two ways. The first is holding it to a strong light, as bone china is structurally strong, but also allows light to pass through. The second is to identify the maker's mark on the piece.
Four of the top bone china manufacturers in England are Wedgewood, Royal Doulton, Spode and Royal Worcester, with each having its own distinct hallmark. Ceramic hallmarks are applied to these pieces in one of four basic ways: incised, impressed, painted or printed.
The hallmark, or maker's (or even potter's) mark designates the manufacturer, and also provides more information such as the place and date of manufacture. For example, in addition to its hallmark of its name written in stylized script, Wedgewood prints a three-letter code on its pieces where the last letter stands for the date the piece was made. (E.g., N stands for 1885). The Spode pieces are marked with the Spode name alongside a pattern number in red. This pattern number started at 1 in 1800 and had already reached 5000 by 1833. Royal Doulton china has the name "Doulton," usually within a circle that sometimes has a lion, a crown or both. The Royal Worcester china has only a crescent moon hallmark on the earliest pieces before later incorporating the full company name. It uses a code system of dots under the hallmark to designate the year of manufacture.