How to make backgrounds transparent?

[NoNZealot]

Well I got a problem on how to make avatars backgrounds transparent. Do I have to use .pngs for this? Or something special?

 

[Teh_Ephy]

Use the GIMP, add an alpha layer to the background. Make sure the background colour isn't used in the actual image.

 

[NoNZealot]

thank you.

 

[HappyTauren]

I think it will be harder on animated avatar though...

 

[Teh_Ephy]

For animated avatars, you can do colour to alpha within the individual layer (which would be an individual frame of the animation) and set the unused colour to alpha (which would make the same area transparent). Again, make sure that the unused colour is unused in the actual image (yes, obvious, but easy to overlook).