What kind of written material can be used without first obtaining copyright permission?

Public domain material refers to written works that are not protected by copyright law, either because the copyright has expired, the work was never eligible for copyright, or it has been explicitly placed into the public domain by the creator. This means that anyone can use public domain materials freely, without the need to obtain permission or pay any fees.

For instance, works created by authors who died before 1923 in the United States are usually considered public domain. Additionally, governmental works in many countries—including certain U.S. government publications—are also in the public domain. This characteristic makes public domain material valuable for education, research, and creative purposes because it allows for unrestricted access to a wealth of resources.

In contrast, original material is still under copyright as it is a new creation; copyrighted material refers to works that are protected by copyright law and require permission for use; unpublished material, while it may not be publicly available, can still be protected by copyright. Thus, public domain material stands out as the correct choice for works that can be used without prior permission.