whether you are a patent owner, or exist in an industry where competitors own patents, it is helpful to know the ins and outs of patent marking.
patent marking is the practice of notifying others that a product is patented (or patent pending) by actually inscribing it on the product. for products with issued patents, this is properly done by inscribing, for example, "Patent 1,234,567" or "Pat. 1,234,567" (whatever the patent number is) on the actual product. putting the patent number on the actual product is important—only in rare exceptions should the marking be done on the packaging instead of the actual product, although it can always be additionally done on packaging. for products with patents pending (e.g., provisional patent applications), "Pat. Pending" or "Patent Pending" is written.
one newish development in proper patent marking provides a considerable amount of flexibility to patent owners and is known as "virtual marking." in virtual marking, "Patent" or "Pat." is written on the product, followed by an internet address where one can find both the product and the full patent number for it.
beyond providing deterrence to would-be infringers, patent marking serves a vital function to patent owners. specifically, under federal law, damages for infringement start upon actual or constructive notice to the infringer. proper patent marking provides constructive notice under the law. where patent owners fail to implement proper patent marking (i.e. constructive notice), they lose both leverage and money because the damages clock will most likely start ticking against infringers when the patent owner's attorney provides actual notice through a cease and desist letter. this is typically after (and sometimes long after) an infringer has seen the product.
importantly, businesses should be careful to avoid false marking—saying something is patented when it is not. this can give rise to liability.
so, if you are not a patent owner, but exist in an industry where competitors own patents, can you usually tell whether a product is patented simply by examining it? unfortunately, no. despite federal law on patent marking, many patent owners don't do it properly. and some engage in false marking, giving the impression that something is patented even when it's not. so, the best way to determine whether a product is patented is to have a patent attorney conduct a patent search.