The copyright holder, or anyone the copyright holder authorizes.
No. Public domain means that the material is available for use by anyone, without copyright restriction.
No, not without permission. One of the rights that copyright conveys is right to display the work publicly. By placing the copyrighted work in your portfolio, everytime you show it you are usurping the original artists right.
No. Unless things have changed, the most accepted form of not breaking copyright with printed material is that up to 1 third of the material may be copied for reference purposes. Any more then that is breach of copyright. Why do you think it's called "Copyright" if any one is allowed to copy it entirely? The "right" to copy it remains with the copyright holder.
You may use copyright protected material when you are the copyright holder, or when you have permission from the rightsholder or an exemption in the law. The most notable exemption is fair use or fair dealing, which allows certain limited unlicensed uses in situations such as education and commentary.
The reproduction or use of someone else's copyright material without permission or license.Copyright infringement is the unauthorized or prohibited use of works under copyright, infringing the copyright holder's exclusive rights, such as the right to reproduce or perform the copyrighted work, or to make derivative works.
Contact the copyright holder and request permission.
A) Use only original material B) Use only material confirmed to be in the public domain C) Find the copyright holder of any other material and, in writing, obtain the necessary permissions.
A copyright gives the owner the exclusive right to reproduce, distribute, perform, display, or license original material.
Infringement is the use, without permission, of copyrighted material that does not fall under a "fair use" or other exception to copyright law,
You would be guilty of copyright infringement, a federal crime.
Unless it would fall under "fair use" no it is not "okay" to use copyrighted material without permission
It just means general copyright, as a concept, as opposed to a specific right on a specific material. A generic copyright letter is basically a form letter to alter as needed.