How does a group of different artworks become an art collection?

The answer is elusive and one of those things that sometimes you just know it when you see it. Other times a group of works is tighly curated so as to form a museum-quality collection. In general, a collection is a group of artworks assembled by a collector with knowledge, expertise, or a particular interest in that type of artwork. Rarely can one just run out and buy a group of things and say “Voila, that is a collection.” Remember that museums have curators and acquisitions committees to select works of art that fit within their existing collection and to guide that collection in its future collecting goals. The good private collections also account for such factors.

Here are a variety of organizing principles for art collections:

geography (such as the art of Mexico)
subject matter (such as marine art, folk art, video, installation sculpture etc.)
timeframe (some people collect mid 20th Century works of art, for example)
“school” – this refers to the work done by a group of school of artists done in a particular time and place, style or method – such as The Ash Can School (it was not literally a school!)
material (such as a collection of art glass or works on paper)
travelogue (artwork collected over the years in various travel destinations)

Many good and well-edited collections combine a variety of factors. The possibilities are endless. Some collections are organized according to the influence of a particular artist on other artists, for example. Other true collectors have a variety of collections. For example, in addition to contemporary landscape paintings one could collect vintage fashion photographs.

Remember, not every piece of art that you have has to be part of a particular collection. Sometimes we just buy something because we like it. However, if you are going to be spending a lot of money on valuable artwork “the collection” is often more valuable as a whole than the individual pieces would be and it behooves you to make a wise decision as to how a work fits with your other pieces.