Many creators of fine (and even not so fine) glass, china and porcelain and even furniture from the past signed their pieces. These signatures can be as simple as an after-making etching of the artist's name or as elaborate as a gold leafed stamp on the bottom of pieces. In some cases, makers' marks are hidden in the pieces so as not to detract from elaborate designs or overall hand-painted effects.
Learning these marks is a fun and interesting pursuit in and of itself. Sometimes glassmakers were so crafty with signing their pieces, looking for the marks becomes kind of a scavenger hunt in and of itself. Some cut glass makers, for example, added their signature into the elaborate design so only those schooled would even have a chance of finding it.
Not all makers of fine glass sign or signed their creations, but many did. Considering this, it's a very good idea to learn the marks, commit them to memory and seek them out before making purchases. Although it's certainly true the marks, in many cases, could be copied in reproductions, many times these marks can work in conjunction with other distinguishing factors to help make determinations about pieces.
Since all glassmakers who chose to use marks had their own distinct style, the best way to learn about them is to study the marks in antique books, online or in other literature about the glassmakers. Many antique books, for example, include a copy of what the signature would look like in an original piece right in the listing for the item. They even tell you where to look.
Even the most intricate pieces might just be signed and these signatures can really help antique collectors find the best and leave behind the knock offs. Learning the marks can be difficult, but it's worth it to make sure a purchase made for an antique collection is a solid one. Plus, it's just plain fun!