Items that existed in the period being studied. This includes but is not limited to paintings, drawings, sculpture, engravings, tapestries, illuminated Tailors Books, effigies, and actual specimens of costumes.

If you, yourself, were allowed to view and touch an extant piece of clothing, that piece of clothing is the primary souce material.

Texts, re-drawings, and other media which present or examine primary sources and use those sources to form opinions and theories of the author. The more accurate and educated the opinion, the better the secondary source.

Janet Arnold's work is an excellent example of a secondary source; it presents primary source information with her theories.

These are such things as re-drawings of paintings, someone's opinion of someone else's opinion, or any other presentation of theories or opinions that does not lean heavily on primary source material. Just because someone published a book does not mean that they are a good source.

An excellent example of this type of source are the texts by Racinet and Peacock.