White (not transparent) background in sprite [graphicsgale]

Just to be clear, I`ve been reading and trying solutions for hours, and I didn't find a similar problem.

The problem: I draw something in GraphicsGale. I save it in my project folder under "Sprites". It has a white background but I wanted it to be transparent.

Things I tried:

• GraphicsGale:

  1. I enabled, in layer properties, transparency (and set it to white).

  2. I set the document background to white.

  3. I Added an "alpha channel" to the document.

  4. Saved as a PNG.

• Unity:

  1. I changed the texture type to "advanced" and tried with "alpha from grayscale"&"Alpha Is Transparent", and "alpha from grayscale"& without "Alpha Is Transparent", and finally without "alpha from grayscale" [the option "Alpha Is Transparent" pops when clicking on "alpha from grayscale" and unity doesn't allow me to check only it].

Solution?

I use graphicsgale because its free (I`m just a beginner). What am I missing? Is this a unity thing or is it something in GraphicsGale?

Thanks :-)