> Going back to the example of the furniture maker. If I just copy his designs roughly but procure the wood myself, learn woodworking, put in the work to saw, sand and hammer the wood into shape, would I be in the clear?

I think more or less yes. There are plenty of makers out there who don't sell the furniture but instead sell the blueprints and instructions on the tools you'll need and how to go about building it, and buying that would be substantially cheaper than buying the finished piece, with the obvious trade-off being you then need to actually, y'know, build it.

That being said these are very ethically gray questions. If you took for example, the rotted and destroyed pieces of a hundred year old hutch, and from them, reverse engineered how to build a new one, filling gaps along the way where pieces you don't have would be, then are you "stealing" from the original craftsman who made that hutch in the 1900's? I think most people would say no, because that artisan is probably long dead and you aren't depriving him of anything by recreating his work. In fact I think some people would say, were he alive, he might even be excited that someone took the care and time to recreate something he put a lot of work into that was destroyed by the passing of time, and appreciate the level of craftsmanship in turn that effort would demand.

However, on the flip side, if you went to a hand-craft furniture shop and somehow convinced the owner of it to let you take extremely detailed documentation on one of their pieces that would normally sell for a substantial amount of money, and assuming you had the skills to accomplish this work, took that home and used it to create your own copy of it, I think the artisan behind it at least might have some feelings about it? People who invest large amounts of time and effort into a craft like that (it's in the name, craftsman) put a lot of themselves into their work necessarily; they can't not, what with the sheer time commitment. But that's a much muddier version: some of them might try and take legal action, others might offer you a job. That's an interesting question.

However I feel it's important that we acknowledge what you're talking about is not the same as taking those detailed measurements and spending many many hours constructing an identical hutch: what you're talking about is essentially right clicking something, clicking Copy, and clicking Paste: this activity takes no skill, no energy on your part, probably some amount of time but that's time spent where a computer is working, not you, and you can go do anything from make a coffee to play a round of golf. The ethics of if you could do this same thing with a piece of furniture are largely irrelevant. You can't.

A more apt metaphor that would bridge the gap better I think would be the hobby/industry of 3D printing. You download objects that are designed by others, some paid for many not, and you plug that model into a slicer program which generates instructions that permit a machine you own to construct an object that is, more or less, identical to one constructed by the author of the file barring things like slicer settings. Many models are available for no charge; more artistic and detailed models, the author sometimes does ask for some money for them, again because of the investment of time and effort on their part spent creating it.

> But on the other hand I would never have bought any furniture from the craftsman anyway, so where is the harm?

The harm is that you have taken the fruits of the labor of another person without their consent and used them to your own end. That's really the beginning and end of it.