To be valid, a trade mark requires a distinctive character: the trade mark must be able to let the average consumer distinguish one undertaking's products and services from those of another undertaking.
When it comes to logos and names, the average consumer is used to this distinctive function being fulfilled. This is less obvious when it comes to the look or shape of packaging materials. Generally speaking, consumers will consider (shapes of) packaging more as a decoration than as a manner of referring to an undertaking. This is why the Court of Justice requires the (shape of) packaging to differ sufficiently from what is customary in the relevant sector, in order for it to be registered as a valid trade mark.
The Court recently handled a preliminary ruling request on the question whether or not it was necessary, for a trade mark consisting of a colour motif on a bus, train, tram or other vehicle, that this colour motif differed significantly from what is customary in the economic sector concerned. The question resulted from a colour motif on a bus of a Swedish transportation company: