Sub Badges

I am an under the radar streamer, I typically don't have many subs or too many viewers at any given time. However for the few subs that I do have, I would like to have some crafty custom sub badges to let them know that I really do appreciate them. I have tried a couple times to get a test sub badge put into twitch but it never seems to let me upload them saying that the size is wrong. If anyone has any ideas or any resources to help me that would be great. The paint program I use is the basic paint program that came custom with the computer. Thanks