Over on the Technology & Marketing Law Blog attorney John Ottaviani notes that the Federal Circuit affirmed, per curiam, the Trademark Trial and Appeal Board, which had denied Pennzoil's attempt to trademark a clear motor oil container (Federal Circuit Refuses to Register Pennzoil's Clear Motor Oil Bottle as a Trademark).

In this case, the most damaging evidence to Pennzoil’s position that the clear container is not functional is that Pennzoil introduced its clear container after it determined that there was an obvious competitive advantage to displaying the colorization of its synthetic oils and blends in a transparent bottle. Because there were numerous non-reputation related reasons for adopting a clear container, and these were competitive reasons that should not be denied to Pennzoil’s competitors, the Board found that Pennzoil did not have a right to appropriate the use of a clear container exclusively for its motor oils....

Will this decision have implications for other products that are marketed in clear packaging and containers? The Board was careful to note that it did not want to set out a per se rule about whether or not there may be other circumstances under which a clear container could function as a source indicator. However, I cannot think of an example where a clear package would both be non-functional and have acquired secondary meaning. At least for now, then, the world is safe from those who would require us to purchase all of our products in opaque containers and packages.