sandchip
Well-Known Member
"The word seam refers to the joining of two like pieces of material. like sewing cloth or welding steel, which never occurs when a bottle is blown, because the gather of glass is always in one piece. The mold lines or "seams" are only the impression left in the glass of where the mold halves or sections meet."
A semantical nicety, indeed. A bottle can be described as a cast made inside a mold. The impressions on the bottle are of the joins (seams) of the mold parts. Those impressions then might be called "casts of the mold seams." But, I think "seams" will survive in our shorthand vernacular.
No doubt, the term is here to stay, sort of like sunrise. But I do want to be on record in opposition to its incorrect use!