Sleeve of Mail
Depicted is a sleeve of chain mail from Germany during the 16th century. Chain mail was made of circular links of metal connected to one another to create a strong, mesh, metal fabric. Chain mail was used throughout Europe as body armor. From around the mid-15th century and after, chain mail was used with full plate armor to fill the gaps in between plates. Chain mail was also used in Asia and by Spanish colonizers.
For a close up on the image follow the "Available at" link.
For more about chain mail go to: https://www.nps.gov/cabr/learn/historyculture/conquistador-clothing.htm
[Sleeve of Mail]. 16th century. Steel. Accession No. 21.183.36. Metropolitan Museum of Art: Arms and Armor. https://www.metmuseum.org/art/collection/search/34857?searchField=All&am... (Accessed January 4, 2018).
Public Domain
Public Domain is a copyright term that is often used when talking about copyright for creative works. Under U.S. copyright law, individual items that are in the public domain are items that are no longer protected by copyright law. This means that you do not need to request permission to re-use, re-publish or even change a copy of the item. Items enter the public domain under U.S. copyright law for a number of reasons: the original copyright may have expired; the item was created by the U.S. Federal Government or other governmental entity that views the things it creates as in the public domain; the work was never protected by copyright for some other reason related to how it was produced (for example, it was a speech that wasn't written down or recorded); or the work doesn't have enough originality to make it eligible for copyright protection.