Each application of fair use must be examined on a case-by-case basis, as there are no absolute rules about how much of a copyrighted work may be copied and still be considered a fair use.
To do a fair use analysis, you need to consider the four factors that U.S. Courts have provided as criteria.
These are:
the purpose and character of your use
the nature of the copyrighted work
the amount and substantiality of the portion taken
Each application of fair use must be examined on a case-by-case basis, as there are no absolute rules about how much of a copyrighted work may be copied and still be considered a fair use.
To do a fair use analysis, you need to consider the four factors that U.S. Courts have provided as criteria.
These are:
the purpose and character of your use
the nature of the copyrighted work
the amount and substantiality of the portion taken