To make your guild logo seem cool, you can make the background transparent with an easy trick.
When you decide which logo you are going to use, you can change the file type from .jpg to .tga .
This can be done with the program Paint.Net (which is free to download from here ).
Follow my steps:
First, you have to make sure your photo is 16x12. If it is not, you can resize it:
Image -> Image size...
Then, with the " Magic Wand Tool " (or "W" button) select the backgroud of your logo:
Press Delete, to delete this content and then Press " Save As " and select the file type " .tga ".
Done! Your image will now be transparent.
example of a non-transparent logo (.jpg) : 
example of a transparent logo (.tga) : 
Enjoy! Best Regards, Factory Team