Intellectual property law is often seen as three separate areas: patent law, copyright law, and trademark law.
Patent and copyright are almost exclusively federal law and find their origins in the U.S. Constitution, specifically Article I, Section 8, which gives Congress the power to "promote the progress of science and useful arts, by securing for limited times to authors and inventors the exclusive right to their respective writings and discoveries."
Trademark and the related trade secret law have both federal and state overtones, arising out of laws governing business practices and fairness and the use of product markings to protect and identify brands, companies, and services.
The Supreme Court case, Star Athletica, LLC v. Varsity Brands, Inc., dealt with cheerleader uniforms, and the lawsuits filed by Tipsy Elves (tipsyelves.com) against the retailers deal with "ugly sweaters."
Coca-Cola did not get any kind of patent protection for the concept of a glass bottle- even a glass bottle with scalloped or ridged raised portions (which might have been subject to a utility patent for serving to strengthen the bottle)- but it did get to protect the bottle's particular shape.
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