Using experimental CSS features in production is a web developer dream! Do you want to extend CSS functionality with your code? During this talk, I will show how to programmatically generate an image for any CSS property that can use pictures with CSS Paint API. We will go from basics to advanced features through amazing practical examples. With few lines of JavaScript, you could create and register own CSS functions similar to linear-gradient. Afterward, you will be able to develop polyfills for a feature from spec draft or create cool backgrounds with code, with safe fallbacks that you can use in production right now.