significance of numbers on bottom of old noxzema bottles?

TLHunter06

Hello! We didn't find a whole bottle, just the bottom of one that washed up in a local lake. It's cobalt blue and has Noxzema stamp on the bottom. (at first, it looked like a rectangle split diagonally with the letters Nox and ema...my husband recognized the "z" in the middle). But underneath it is a number "1". I've seen others on Ebay with higher numbers like 9 and was just curious if there was any significance to the numbers? Thanks!

p.s. - the picture I posted isn't of ours but it's exactly the same, only difference is that ours has a number 1 below the stamp.

historic

A single number like this is probably a mold mark. A production bottle like this could have been made in one of many different, identical molds. Consider that an identification number could help with quality control in the event that there was a problem with one mold in particular.

Other base markings have been used to identify the plant at which the bottle was made, date of manufacture and of course the company.