Q: Can the ESB shadow in a 1937 photo be trademarked?

A: This question sits at an interesting intersection of trademark and public domain law. While the Empire State Building's distinctive appearance is trademarked by the Empire State Realty Trust, a shadow presents a unique case that hasn't been clearly established in trademark precedent. The building's trademark protection typically covers uses that might create confusion about commercial source or sponsorship, but a shadow in a public domain photograph from 1937 represents several degrees of separation from the protected mark itself.

When considering your use of this historical photograph, remember that public domain status addresses copyright but not necessarily trademark concerns. The shadow occupying only 17% of the image and showing just a partial resemblance to the building's shape works in your favor, as it's less likely to be seen as directly using the protected architectural design as a commercial identifier. The age and historical nature of the photograph also suggests this would be viewed as documentary rather than exploitative use.

Looking at similar cases, courts have generally required more direct representation of trademarked buildings in commercial contexts to find infringement. Your reproduction of a public domain historical photograph where the building itself isn't even visible represents a significantly attenuated connection to the protected mark. While I can't guarantee how this specific situation would be interpreted legally, these factors suggest the risk of trademark issues is relatively low compared to selling reproductions showing the actual building. You might consider consulting with an intellectual property attorney who could evaluate your specific circumstances if you remain concerned.