Often paintings, prints or drawings only (or sculpture, ceramics, etc., if appropriate) are discussed in a particular catalogue, and sometimes only a certain period of the artist's life is covered.
It contains most of the information a researcher will need up to the year the catalogue raisonné was printed. In particular they are important references for attributions — which paintings are actually by a given artist.
A catalogue raisonné may be regarded as the prime source of information about an artist's work, and allows one to see the full range of work in sequence.
Because artwork can be widely distributed, and some owners may not wish for high-quality images to be made available, some photographic reproductions of works may be only in black and white and/or small in size. Works since destroyed may exist only as old photographs or prints.
Catalogues raisonnés are typically expensive to produce because of the sheer volume of pages and photographic reproductions required, and generally have a limited market. Thus, they usually carry a high price and are rarely reprinted.
The term catalogue raisonné is French, meaning "reasoned catalogue" (i.e., containing arguments for the information given, such as attributions) and has wide usage in English. Accordingly, the spelling is never Americanized to "catalog", even in the United States.