It came out pretty good this time!
Two other things need to be done though, and that the resist should actually be printed in reverse... I want the areas in black to be etched in, so I bungled that. And I would also like the maple leaf to be on the right. I'll keep that in mind for the next attempt, this test should be good enough to begin some actual etching!
Edit: Aaaaand I've got a version with the reversed and flipped image. It's all good! The tears at the edge are simply caused by the metal not being flat. I used a pair of shears to cut the metal, and this was what caused the warping. Gotta see how I can cut metal without the warpage - maybe a jewellery saw?