Dating o i bottles

The disk-like mark is sometimes confused with a pontil.the pontil is actually broken glass where the metal rod used to hold the bottle while the lip was form was broken off leaving a sharp scar.However, there are some exceptions to this general rule, and single-digit date codes were also used in later decades along with the later “I inside an O” mark (but without a period placed to the right of the code).Most bottles from the late 1940s into the 1950s and 1960s have two-digit date codes.On many bottles, a single-digit date code along with the diamond/oval/I mark may indicate the 1930s.From information compiled in Bill Lockhart’s article (link below) on Owens-Illinois’ date code markings, it appears that, on containers with this earliest trademark, if a single digit date code (such as “O” or “1” placed to the right of the logo) the chances are very good the bottle in question dates from the 1940s, especially the 1940-1947 period.

The second mark was phased in during the 1950s with the removal of the diamond.There was a gradual changeover from the “old” to the “new” trademark on containers which occurred over a period of four or five years beginning in 1954 (with a few known exceptions—see note below discussing a bottle made in 1966 with the “old” trademark).Some bottle molds already in use were not re-engraved until as late as 1957, 1958, 1959, even, as mentioned, in 1966. “OWENS” appears on the base of some clear prescription bottles.Dating antique bottles requires knowledge of the evolution of bottle technology and the ability to research manufacturers and bottling companies.Although glass bottles have been made for a few thousand years, it was not until the 19th century that bottle use became common, coinciding with the industrial revolution. The earliest bottles were hand-blown by a glassblower with a blowpipe and lack seams.