Prior to improved glass blowing and
bottle making techniques in the 17th century, most bottles were
sealed with pieces of wood that were strapped or lashed in place
with string, twine or leather straps. A String Rim was a
thick band of glass on the upper neck of a bottle around which the
strap was secured.
Today a much smaller version the String
Rim still exists on wine bottles as a holdover from the early days.
It only has real value in modern times in the bottling of sparkling
wines where the wire hood which secures the cork is fastened around
the string rim.