Basically there are 3 things to consider with public domain criteria.

They are:

1. Date of Work - What year was the work created/produced
2. Protected - What copyright protection were issued at creation
3. Term - How long is the work protected

In a general definition any work created before 1923 usually has no protection or term. There are exceptions to this though they are rare. On the other hand almost all work created from Jan 1978 and on is copyright protected. Usually the term for the copyrights are life +70 years, or in the case of a corporate copyright it is life +95 years.

This means that anything created since Jan 1978 is copyright protected for the life of the original creator and at least 70 years beyond his or her's death.

Between the years 1923 and 1978 the copyright laws were changed several times and most works were granted protection for 28 years initially and if renewed for another 67 years beyond the first term's expiration.

But this was not always the case. as the laws changed 4 times during this period of time and lots of works did not get copyrighted at all or were never renewed.

So a safe bet when you are searching for public domain works is anything created before 1923 is probably safe to use any way you see fit. Works created between 1923 and 1978 you should be cautious about using because they may still be copyrighted.

And finally anything created after 1978 you can bet is copyrighted and you must seek permission to use the item or work.

About the Author

There are 85 million works such as songs, videos, sheet music, mp3s, books, pictures, and works of art now defined as public domain. My free eCourse helps you find and use public domain efficiently. http://www.publicdomaingoldrush.com