Legal Question in Intellectual Property in Illinois

In general, the better practice is to trademark every single design and phrase. You should contact an experienced trademark attorney to fully understand the facts and the law plus the filing costs involved.

You can file a single trademark application to register the name of your entire clothing line, e.g. "Tommy Hilfiger," if that name appears on all your garments. If some of your garments carry separate designs, separate applications to register these may be filed. Note, however, that the U.S. Patent and Trademark Office will not register clothing designs that they deem to be "ornamentation." For example their rules state that it is a matter of common knowledge that T-shirts are "ornamented" with various insignia ... or � various sayings such as "Swallow Your Leader." In that sense what is sought to be registered could be construed to be ornamental. If such ornamentation is without any meaning other than as mere ornamentation it is apparent that the ornamentation could not and would not serve as an indicia of source, that is, as a trademark. Thus, to use the Patent Office's example, "Swallow Your Leader" probably would not be considered as an indication of source or a trademark. However, the "ornamentation" of a T-shirt can be of a special nature which inherently tells the purchasing public the source of the T-shirt, not the source of manufacture but the secondary source....and act as a trademark and, therefore, be registrable. For example, ornamental matter on a T-shirt (e.g., the designation "NEW YORK UNIVERSITY") can convey to the purchasing public the "secondary source" of the T-shirt (rather than the manufacturing source).

Also see http://markscounsel.com/?p=7