What are straw marks on glass?
The answer is straw marks are surface lines (either in or raised from the surface) in glass that occur during the cooling of it. These lines originally got their name from the days when glass was placed on straw to cool. Some straw marks can appear to be cracks or even scratches, but a discerning eye can usually tell the difference. Straw marks generally have a rough finish to them, compared to a scratch. If it is raised from the glass, you can be sure it is a straw mark, a mold line, or perhaps something that was designed to be there. Straw marks are found on EAPG glass(almost as a rule!), art glass, depression glass, and many other forms of glassware. The example picture is from Fenton that was made probably in the 1970s in a popular pattern called hobnail.