How to preserve image quality when putting image on a cube for buttons

I’m using buttons made out of a thin cube with a picture on it. I’m using this instead of onGUI to improve game performance. However, when I put the icons (pngs) on the cubes, they look distorted. The edges look ragged and the whole image looks muffled.
I already checked that it wasn’t because the picture was too small or big for the cube. It also doesn’t help to adjust the camera distance. Could you please advise on how to make a picture on a button look as much like the original picture when it’s in unity?

Here’s an example:

original picture1255-Info.png

picture on a unity cube (you can ignore the black background):[1256-iChat+Image(383281963).png|1256]

Try doing both of these:

  1. Change the Texture Type from “Texture” to “GUI” in the texture settings of the Info texture.
  2. Change the Format from “Compressed” to “Truecolor” in the texture settings of the Info texture.

Also, I’d use a 4-vertex plane instead of a cube if I were you.