Copyright law pertains to works of visual art as well as to music, writing, film, and other forms of expression. In art copyright applies to paintings, illustrations, sculptures, photographs, etc. Works that have some practical use such as in industrial design and fashion are protected by patent and/ or trademark law. In the United States, works of art are automatically copyrighted when they are placed in any tangible form. One can register a copyright with the federal government, but it is not necessary in order to gain copyright protection. For works created after January 1, 1978, copyright protection generally lasts for the life of the artist plus 70 years. Works for hire, that is, done on commission, have different terms.
In general, the creator of a work of art is the owner of the copyright. He/she can determine if the work can be copied or distributed. A person who wishes to use such work must seek permission from the copyright holder (and possibly pay, if required). It is not enough to credit the creator in order to satisfy copyright law.
The concept of “Fair Use” entitles people to reproduce the works of others without seeking permission if certain conditions are met. These include whether the use is for non-commerical or educational purposes, whether the use involves commentary or satire, the extent to which the original work is transformed in the use, and if the use of the work does not compromise the monetary value of, or revenue from, the original work. Fair Use is an extremely complex concept and there are no clear legal guidelines such as the percentage of an original work that can be safely copied.
As with all laws and regulations, this is subject to change.