 How do I know when art resin is fully mixed and ready to use? Art resin comes in two parts, a resin and a hardener, and when those two parts are combined and you stir, you cause a chemical reaction to happen, which will turn that liquid product into a solid. So how do you know when you've stirred it enough? Well, generally we say three minutes is a good rule of thumb, making sure that you scrape the sides and scrape the bottom as you go to make sure the whole mixture is indeed fully mixed. So put on your favorite song, put on a timer, but just make sure you get to that three-minute mark. And one word to the wise, if you're pouring that mixture out, don't scream out that last little bit because if anything is going to be unmixed, it will be that last little bit. Just a percussion.