Identify glass manufacturers marks by cross-referencing the glass's mark with a glass markings database such as the ones available on GlassLoversGlassDatabase.com and 20thCenturyGlass.com. Other information about the glass piece helps narrow down categories in which to search.
The databases of glass manufacturer markings on GlassLoversGlassDatabase.com and 20thCenturyGlass.com categorize markings by country as well as date. Therefore, knowing the glass's country or date of manufacture provides a starting point so that you don't have to manually scan every image within a database for similarities. If you do not know these facts, it is possible to use a secondary database to obtain one or both pieces of information.
Sites such as the Historic Glass Bottle Identification & Information Website, a division of the Society for Historical Archaeology, provide alternative methods to find out where and when a glass piece was made. In addition, this site provides information about how the glass was manufactured as well as its type and possible uses. This site provides information about glass made in the United States and Canada.
To start, visit SHA.org and select Historic Bottle Identification from the drop-down menu under Research Resources. Once redirected, select Dating from the sidebar menu. This page guides you through the process of further classifying the glass by asking for specific details, such as whether the embossing is raised, whether the glass has visible side mold lines, and what shape the glass has.