Mc has very patiently explained the particulars of this issue to me in
IRC, and we worked together to come up with this:
http://i.imgur.com/moaKwfo.png
Wow, perfect! This mostly solves my concerns I outlined in the
relevant Launchpad bug while at the same time making it much easier
for most users to make a good choice with less thought!
There's two things that could use improvement:
A minor thing: "Pixel-based artwork" sounds a bit like
pixel-art (which is not what this is about). Maybe call it
"artwork based on dimensions given in pixels" or similar?
The two selections for "physical output" do not really well
explain what the difference between them is. Both selections
mention that they are for content that "needs to be accurate"
but the accuracy we're talking about is obviously different in
both cases.
Best regards and thanks for the really well though out mockup,
Eduard