Do UV maps need to be Square?

I have a “plane” object that is 10 wide and 20 tall. When I UV unwrap it it fills only half of the 1024 x 1024 UV map, so I wanted to create a new uV map that was 800 x 1600 pixels in size so the UV map would match the plane in size.

I’ve read somewhere that you should keep your UV maps “Square” in shape (For e.g. 1024 x1024 instead of 1024 x 512) but I can’t remember why? Is it really that important or can I make my UV map a rectangular shape?

pg

There is a mode for this. I can’t remember what it is, but it can probably be accessed from the UV window. I’d check the release notes for 2.4, because I know it is a recent thing.