How could redistribution clauses common to copyleft licenses (paraphrased below) be applied to purely hardware products? i.e. products that contain no software or firmware but where all design documents are copyrighted under a strong copyleft license.

anyone who redistributes the software, with or without changes, must pass along the freedom to further copy and change it

Is there a way to enforce the requirement that the product be provided to the users with access to all documentation and source information required to reproduce it? Additionally can this right be extended to modifications of that physical product?

I've searched SE and found one answer [1] which does indicate that the physical product cannot itself be copyrighted but it's not clear to me where the line is drawn in determining the extent of rights conferred to the user from the license used to create the product.

If I released a copyleft piece of clothing (all design/manufacturing documents are copyleft), could I require that any manufacturer that produces it include the license, attribution, and documentation (or a link) "in the box" with the physical product?

Would a retail store that acquired this product then be able to bypass the intent of these conditions by removing the documentation, license, and attribution from the box, packaging it back up, and selling it to a customer that way?

At what point would this restriction stop? Would a user/customer be able to re-sell or give the product to another user if they lost the license/docs? In the event they made modifications to this product (repairs, etc), would they need to document those changes to be able to transfer ownership of the product to another person and if so to what degree would they need to do so?

  1. https://opensource.stackexchange.com/a/1081/22149
  • 2
    The clause you quoted is not what the license actually says, but rather it's the principle behind the license.
    – user253751
    Feb 22, 2023 at 3:39
  • 2
    Typical practice is that products including copyleft software will provide a URL where you can download all the source code, but there's no reason you couldn't require it to be a CD or a USB stick.
    – user253751
    Feb 22, 2023 at 3:40
  • Ah good point. I just did a quick search for the wording but I wasn't exactly looking for anything verbatim. Rather I was just focusing on the general intent behind it and the question focusing on general application of copyleft to HW rather than anything license specific.
    – Jacob Abel
    Feb 22, 2023 at 5:22
  • I believe it is close to impossible to answer your question, because on the one side you ask if there could be a strong-copyleft open-hardware license (which to my knowledge currently does not exist), and then you ask if that -yet unwritten- license would allow the downstream enforcement in several corner cases. Feb 22, 2023 at 11:31
  • Another thought is around the first-sale doctrine, which is a legal concept in USA and other countries that limits the influence of the rights holder (or original manufacturer) of a product after it has been legally sold. The first-sale doctrine will make it difficult to enforce a permanent strong-copy-left link between the design documents and the physical product. Feb 22, 2023 at 19:36

1 Answer 1


tl;dr: How could redistribution clauses common to copyleft licenses be applied to purely hardware products? They can't, and shouldn't.

The problem, it seems to me, is that hardware isn't software. The very things that make the GPL more suitable for software (awareness of the existence of source code, requirement for its ongoing free availability) make it a lot less suitable for hardware, and arm-waving about the effective equivalence of source code and design schematics doesn't make it any better.

What you need is a licence specifically intended for FOSH (free/open-source hardware), such as the TAPR Open Hardware Licence. You can read through that, see how it distinguishes between documentation and product, and how it handles both. It's not a perfect licence, but at least it emerged out of community discussion.

  • I agree with your answer, but feel that something is missing: If Bob takes the widget and copies it (without use of the documentation) or modifies it, repairs it, upcycles it, etc. (turning it into widget_2), then Bob is free to sell/distribute widget_2 without being required to do so under the terms of OHL. Feb 23, 2023 at 11:09
  • Copies it? No; that infringes the reproduction right, which is not extinguished. Otherwise, I believe so, yes. What are your thoughts?
    – MadHatter
    Feb 23, 2023 at 11:18
  • 'Reproduction Right' is a term out of the area of copyrights, which -as we all know- does not apply to physical objects that are purely utilitarian. There we would have to look at Industrial Design Rights to have any copy protection. But even with a design patent in your hands you can never be sure. Feb 23, 2023 at 12:40
  • The more I think about this, the more I agree with you. I'm editing my answer to restrict it to the advice to use a hardware-specific licence, and say no more. I am grateful for your thoughts on the matter, which have definitely helped sharpen my thinking. As for your original question, I think it's a good one, and maybe worth asking if meta thinks OHL interpretation is on-topic for this site, but it's not this question.
    – MadHatter
    Feb 23, 2023 at 12:50
  • While generally copyright isn't applicable to most types of hardware/physical products, seemingly clothing can be. Somewhat similarly, integrated circuits are covered by mask work protection which are under the umbrella of the US Copyright Office and which provide copyright-like protections to the physical silicon of ICs despite being purely functional in nature.
    – Jacob Abel
    Feb 24, 2023 at 5:56

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