How to Detect Fake Antique Bottles

Examine how the bottle was formed. Bottles made before 1910 were blown while the molten glass was encased in a wooden two-part mold. A slight seam of glass will appear on the sides, indicating where the two parts joined. If the seam goes all the way to the lip of the bottle, it was made after 1910. If the seam stops short of the lip, the bottle was made before 1910. Modern glass will have no visible seam in most cases. Look for the mark of a "pontil" on the bottom of the bottle too. This indicates where the glass blower held the bottle with a rod to steady it during the blowing of the piece. Look for any numbers or letters molded into the base of the bottle. Such identification numbers would tend to date the bottle as being made between the Civil War and the present: really old bottles weren't identified like this. Bottoms marked with the letters "CB" inside a circle indicate manufacture from 1910 to 1960. Any date stamp found prior to 1850 is a fake: real bottles from this time period weren't dated in this manner. Finally, examine the lip of the bottle. If it appears to be applied as a separate piece the bottle is real. If the lip is molded into the body of the bottle, it's newer than 1890. If the lip features screw threads, it was made after 1910.

Judge the age by the color. Really deep, vibrant colors in glass were not possible before the modern era. If you have an "antique" bottle that is wonderfully deep blue, red, or green, chances are high it is a fake. Antique bottles made before 1910 will tend to be clear, shades of brown, or more transparent shades of blue and green.

Determine true age by the quality of the glass. Antique bottles, 100 years or older, will often appear to have small bubbles or blisters inside the glass, reflecting less than modern "perfection" either in the raw glass products used or the glass blower's skills. But beware of "old" bottles that are really badly bubbled or even misshapen. Bottle "fakers" are creating these imperfections to "sell" their fake wares, but real glass artists from the period didn't make bottles that bad! Such a "bad" bottle would have been rejected by glass blowers on pride alone.

Ask the dealer questions if you have doubts. If the dealer won't talk about the bottle with you, chances are he knows or suspects it is a fake. He will be hesitant to verbally deceive you or guarantee authenticity and will try to avoid discussion in too much detail.