Get Photoshop for Mac, first of all.  Gimp is ok but for fine postworking you'll need a different program with a lot more capabilities.

I, too, have used Studio since it was in Beta testing and I've never been a fan of the renders.  This is primarily due to the lighting limitations.  I have, probably, a thousand different lights for Poser but they don't work the same in Studio so about the only thing I do in Studio now is test my product packages and run Shader Spider to save the materials in Studio format.

I don't know if there are any free programs like Photoshop for Mac.  IMHO, if there are, they won't have all the functions that Photoshop does.  Of course, since I work on a PC I don't have a lot of experience with Mac software but I do know that Adobe has Photoshop for Mac but I don't know the price point.

Hugz from Phoenix, USA

Victoria

Remember, sometimes the dragon wins. Correction: MOST times.