Logos and Copyright
According to Section 202.1 of the federal copyright regulations, not everything fixed in tangible form qualifies as an original work of authorship protected by copyright. In particular, a single word or short combination of words is not subject to copyright, which means that a logo consisting solely of a slogan or name is not protected against copyright infringement. However, such a logo may nonetheless qualify for protection as a trademark.
Logos as Trademarks
Trademark protection can apply to a word, phrase or symbol that is used to identify and distinguish goods used in commerce. Whether or not a logo is subject to copyright protection has no bearing on its eligibility to be a trademark. Like copyright, trademark law protects against infringement, but this protection can be limited to the specific categories in which the mark is registered. For instance, while names such as Batman or Wonder Woman and phrases such as "up, up and away" are all registered trademarks for use on clothes, they do not have copyright protection.
Logos and Artistic Design
Nonetheless, as the Copyright Office observes, a graphic design is subject to copyright. Not only does this mean that a design placed on a T-shirt is protected against copyright infringement, but a logo might also qualify for copyright protection to the extent that it consists of an artistic design. For instance, in cases brought by the creator of the Baltimore Ravens logo against the National Football League and more than 100 retailers, courts have found that the logo, consisting of a stylized image of a raven, is subject to copyright protection. In addition, a logo consisting of a graphic design may also be trademarked.
Copyright protection is automatic. Even if a design is not registered with the Copyright Office, its creator holds the copyright and has the exclusive right to profit from it. However, as the Digital Media Law Project explains, registration provides a public record of copyright ownership and is also necessary for filing a lawsuit to enforce the copyright against an infringer. In order to register a design printed on a T-shirt, the copyright holder must file Form VA (for "visual arts") and pay the required fee. The filing must also include two deposit copies of the artwork being registered.