Is it possible to make a .png (or other) image that does NOT have rectangular dimensions?
Solution 1:
All image formats (even vector) must maintain a rectangular border specifying the size of the image. However, one can use the transparent properties of PNG images to simulate the appearance of a non-square image.
Just create your image/shape, ensure the background is transparent, and save the file in the PNG format. Make sure you include the alpha channel so there is a transparent background saved with the image.