Most authorities consider the actual definition of the term 'antique' to mean an age of at least 100 years. If an item is not definitively datable to 100 or more years in age, it should not be directly referred to as an antique. Vintage is a term applicable to a wider variety of objects, including items that may or may not be 'antique.' An item described as 'vintage' should speak of the era in which it was produced. Vintage can mean an item is of a certain period of time, as in "vintage 1950's" but it can also mean (and probably always should) that the item exhibits the best of a certain quality, or qualities, associated with or belonging to that specific era. In other words, for the term vintage to accurately apply to it, an item should be somewhat representational and recognizable as belonging to the era in which it was made.
As a general rule, 'vintage' should not be used in reference to objects less than 20 years old. Like new wine, the present era has yet to develop individual characteristics that posterity can attribute to it. While an antique may usually also be considered vintage, the opposite is not always true. A 'pop-art' item from the 1960's, for instance, could be described as vintage, but it would not yet be antique. (Ruby Lane)
I’m a huge fan of Vintage posters. One day I hope to have a room dedicated to my favourite Vintage Poster. Antiques are wonderful, but I’m more for the vintage things.