When you mix Make Up Store's Mixing Liquid with eye shadow, you get a waterproof eyeliner, which I wrote about in this post.
Now I tried for fun to mix the liquid with red eye shadow and paint the lips with, and the result was actually above expectations!
Mixing Liquid is probably not very good to wear on the lips often, as it dries out the skin a bit. In addition, it is quite difficult to improve during the day. But it lasted a very, very long time, even though I drank several cups of coffee quite carelessly.
So I can probably say that it became waterproof, but not rub-proof like the eyeliner when it disappeared later in the day.
Like a lip liner or when you have to look good in the rain for an hour (maybe before a shoot?) So why not :) It was at least fun to try!