15.18 Infringement-Likelihood of Confusion-Factors-Sleekcraft Test is a legal test used to evaluate the likelihood of confusion in trademark infringement cases. It is also known as the Sleek craft analysis or the Polaroid test. The test was established by the U.S. Supreme Court in the 1979 case of Linwood Laboratories, Inc. v. Ives Laboratories, Inc. The test is based on eight factors that consider the similarities and differences between the marks, the strength of the marks, the similarity of the goods and services, the marketing channels used, the degree of care exercised by customers, the defendants’ intent in selecting the mark, and the likelihood of expansion into related markets. There are two types of 15.18 Infringement-Likelihood of Confusion-Factors-Sleekcraft Tests: the ‘likelihood of confusion’ test and the ‘dilution’ test. The former is used to determine if a mark is likely to be confused with another mark used in commerce, while the latter is used to determine if a mark will be weakened or diluted through unauthorized use.