16oz Reusable Lid for Disposable Cups

My family goes to our local amusement park a lot, and they don't ever give you lids for your cups. We needed to be able to keep our drinks from splashing out of the cup and spilling all over when we were walking with our drinks, so I developed a lid just to keep the cups covered. 

I eventually added a version with a sipper and a  version with a straw hole.

This is designed for a 16oz cup with about a 3.5in opening. If your cup is bigger or smaller, you may be able to scale this to work. 

Note: Print at your own risk. It's plastic you're putting near your mouth, so use your own judgement on how safe that is.