Knowing whether you can legally use a work or not can be tricky. One problem is that there is not a clear cut rule for determining copyright. There are a lot of factors, including:
Date of the original publication: Copyright is not forever. Once copyright expires, the work then moves into the public domain where it can be used freely without permission. Unfortunately, the date copyright expires depends on several factors. For works published in 1978-current, copyright often is 70 years after the author's death. See the public domain chart for more.
How the work is going to be use: In most cases, you can use copyrighted works for educational purposes under Fair Use as long as you give credit to the original owner. You can also use copyrighted works for criticism, commentary, news, parody and archival purposes.
Who created the work: Some works, such as most works created by the federal government, are automatically in the public domain. This means you can use the work (again, make sure you give credit). Also, the rules for "works for hire" are different than normal copyright. If an artist creates an image for a company, it is the company, not the artist, that owns the copyright. Finally in some cases, creators willing give up copyright and publish an open access license, such as Creative Commons, that allows their content to be used without permission.
Public domain refers to works that have had their copyright expired, given up, or that copyright doesn't apply to (such as government publications). Works in the public domain can be freely used without permission. This chart shows the expiration date for most copyrighted items based on authorship and year of publication:
| Date of Publication | Conditions | Copyright Term |
|---|---|---|
| Before 1929 | Expired. All pre-1929 works are public domain. | |
| 1929 - 1989 | Published without copyright notice | Public domain |
| 1929 - 1963 | Published with copyright notice, but copyright not renewed | Expired |
| 1929 - 1963 | Published with copyright notice and copyright renewed | 95 years after publication date |
| 1964 - 1977 | Published with copyright notice | 95 years after publication date |
| 1978 - current | Published with copyright notice | 70 years after death of author. If corporate author, 95 years after publication or 120 years after creation, whichever comes first. |
| 1978 - current | More than one author | 70 years after death of last living author |
| 1978 - current | Anonymous or pseudonymous works | 95 years after publication or 120 years after creation, whichever comes first. |
| Anytime | Government publications | None. Public domain. |
