Dating shows on t v Cm to cam chat with strangers
(Mold seam thickness and how high it protrudes [height] is of only moderate use in telling a machine-made bottle from a mouth-blown bottle, though if a bottle fragment has a hair fine mold seam, it is highly likely to be from a machine-made bottle.) 3.
There are at least two additional finish related mold seams - one at the top of the finish which encircles either the bore or sometimes the outside of the upper lip portion of the finish (sometimes of these seams are present) and a horizontal seam immediately below the finish which circles the extreme upper neck (called a "neck ring parting line").
The offset is a function of the orientation of the parison relative to the two molds (parison and blow molds) used on the particular machine, or occasionally, to the hot parison "sticking" to the neck ring of the parison/blank mold when transferring to the blow mold (Ceramic Industry 19-15).
There are also no horizontal tooling marks present on the finish and/or upper neck as would be observable on the finish of mouth-blown bottles.2.
the suction scar on the base (point #5 above and picture to the left) can date no earlier than 1905 and are usually post-1910.
Though patented and first used to a limited degree in 1903, the first Owens Automatic Bottle Machine licenses were granted to other manufacturers in late 1904 making 1905 the effective "beginning" (i.e., terminus post quem) date for bottles with all of the above listed machine made diagnostic characteristics (Miller & Mc Nichol 2002).
Click on ghost seam to view a close-up explanatory picture of this attribute.
(Note: the term "parison mold" and "blank mold" are synonymous for the first mold in the two mold machine process.): (see the Note box below point #3 for an exception) run up to the highest point of the finish and often onto the extreme top finish surface (i.e., onto the rim or lip).
Earlier machine-made bottles (1905-1920s) tend to have somewhat thicker/higher mold seams than later machine-made bottles due to the increasing precision in mold machining and machinery in general as time progressed.
Most machine-made bottles have mold seams about the thickness of a hair while most visible mouth-blown mold seams tend to be several times as thick, higher, but more rounded.
Press-and-blow machines usually have a round valve mark on the base but lack either the suction or parison scars.
In any event, the suction scar is found on mouth-blown bottles though suction scars are sometimes referred to as a pontil scar by the unfamiliar.