Acceptance often occurred over a period of many years or decades in some cases.This technology lag makes some diagnostic characteristics better than others for dating. As a corollary to #1, consider the following quote: "Treat terminal dates with care.See the Bottle Typing/Diagnostic Shapes page for more information on the subject..
This bottle dating "key" is a relatively simple "first cut" on the dating of a bottle.
While running a bottle through the key questions, the user is frequently directed to move to other website pages to explain diagnostic features and concepts as well as to add depth and/or precision to the initial dating estimate.
All this adds to the fascination with bottle making, but makes systematic dating similar to solving Rubik's cube - ostensibly simple on the surface but complex in practice.
To misquote an old saying as rephrased by the BLM supervisor that facilitated the initiation of this website project: "The universe (of bottles) isn't just more complicated than you think, it's more complicated than you CAN think." True to a large degree, though much information can be teased out of most bottles with a systematic approach to the matter. This Bottle Dating page (and website in general) is designed to address what the website author refers to as "utilitarian" bottles & jars (click for more information).
A substantial amount of bottle type specific information must be reviewed by a user to increase the probability of dating accuracy.
Additional reference materials outside of this website must often be consulted to narrow down the date of any item as far as is possible and to really get a "feel" for the history of the bottle in question.Please be aware that in order to gain the maximum information about any particular bottle (e.g., dating, typing) the user must usually must review a number of pages within this website.Unfortunately, the complexities of precisely dating bottles is beyond the scope of any simple key.In short, there was (and is) nothing to stop a glassmaker from using an obsolete method in the production of a bottle.3.Some technological changes were expensive and not adopted by glass makers until it became an "adapt or perish" issue and many glass factories just perished.Utilitarian items include canning/fruit jars and figured flasks since they were intended to be reused by the purchaser and have been observed to follow well the dating guidelines, though there are some manufacturing timeframe differences with canning jars.