So, you're recording Iron Snout gameplay? That's great! Don't worry about a thing! I just want to help. First of all, you're free to monetize your video!
Second, there is an album of high quality transparent images from the game, which you can use to make some sweet sweet thumbnails:
http://imgur.com/a/d5aZH
Thank you!
More info:
http://steamcommunity.com/app/424280/discussions/0/458607699607842680/