> By that yardstick, most textbooks and eyeglasses are not free. I can't improve a textbook .... I can't put my improved sunglasses on the market (even if it was non-profit).
Yes you can - the product in that case is physical, not digital. You can certainly turn the pages of a book into an origami creation and sell that on a secondary market if that's what you want to do. You can sell modified copies of physical products to your heart's content.
Yes you can - the product in that case is physical, not digital. You can certainly turn the pages of a book into an origami creation and sell that on a secondary market if that's what you want to do. You can sell modified copies of physical products to your heart's content.