This term is used by many and misunderstood by most of the general public. In the most generally accepted context of the word and the “official” definition used by the United States Customs Service, the word antique is used to describe something that is at least 100 years old. Obviously with this definition, the scale slides up every year as time moves on. U.S. Customs also adds a quality standard to their definition in that, while it is acceptable to repair or restore an antique, the item must retain its original character and be less than 50% restored to be considered an antique.
The word antiquities is often used for items that are several hundred years old and are from ancient civilizations such as Ancient Greece or Egyptian. So using the 100 year mark as a starting point, items from 1917 or earlier would currently qualify as an “antique”.
What is Vintage?
Although widely misused, the term "vintage" refers to an item that is at least 20 years old or more but not yet 100 years old. Many people use the word vintage when “retro” would be more appropriate. The word “collectible” is also used in a similar way to indicate something that is not old enough to be an antique yet is older than 20-25 years.
So What is Retro?
Retro refers to an item whose style or design does not match that of the current design trend. Typically it is also applied to a style that has cycled back into interest yet looks like an earlier period. For example the current interest in Mid-Century Modern (1950-60’s).
What is a Collectible?
The best way to think of collectibles is to recognize that there are three common types of collectibles. Artistic and historical treasures less than 100 years old make up the first category. These items are valuable and will remain valuable after they become an antique, such as a Tiffany lamp.
The second kind of collectibles is something that is mass-produced but that may not have any individual artistic merit. Beanie Babies, Hummel statues and even Pokémon cards fit into this category. Commemorative items such as plates and “limited edition” items marketed to artificially inflate an items price fall into this category. The value of these items rarely increases over time.
The third type of collectible is an object that gains value because of its associations. A Marilyn Monroe dress became a collectible almost as soon as she took it off; the sequined one she wore while singing "Happy Birthday" to former President John F. Kennedy is even more valuable because of this association.
All collectibles become antiques after they hit the 100 years in age. However that does not mean that they will be collected or considered of greater valuable.