I want to associate some custom image to my new perks and im looking for the spec of the images accepted by the GECK (size, weight, etc.) Anyone know where i can find this information?

Thanks

Most of the icons in the game are 256x256. Don't know what you mean by weight

The format required is dds. All icons uses alpha channel for the pic itself, on the main layer therre is nothing than just a white color. So you would need to save it in DXT3 compression. Mipmaps are not needed.

As pintocat said, icons are usually 256x256, never tried with bigger pics for what I know you can use bigger sizes, no idea if it will be autoresized ingame.

The weight should be around 65 kb, if you mean that by weight.