Render your image on a black background.  Then save as a .png file. The .png file is considered "lossless" so your image isn't degraded.  When you open it in a program that supports transparent alpha channels, the image has no background.

I know that some save it as a .tiff image. But when you do that you have to appy the image to itself as a mask in your graphic program to get rid of the background.  Saving as a .png doesn't require you to do that.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi