Use manufacturing evidence, marks, seams, finishes, bases, closures, and multiple clues together before assigning a date or maker.
Numbers, maker marks, valve scars, suction scars, and base embossing.
Corks, Hutchinson stoppers, crown caps, lightning closures, and screw finishes.
Decode companies, cities, contents, glasshouses, and mold identifiers.
Use manufacturing clues together rather than trusting one feature in isolation.
A practical inspection order for seams, finish, base, glass, embossing, and provenance.
Applied lips, tooled finishes, crown tops, threads, blobs, and specialty closures.
Where the seam ends can help distinguish applied, tooled, and machine-made finishes.
Open, sand, iron, and improved pontil evidence and what each can suggest.