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?