Mr. Masking Sol Kai (modified) boasts an improved formula that allows smoother application and easier removal to make your masking jobs even easier. Just apply with a brush on what you want to mask, wait 20 to 30 minutes, then trim with a hobby knife. Paint as usual, and when it's all good and dry, remove Mr. Masking Sol Kai with tweezers or a toothpick. Voila! You've got a beautifully finished model. It's water-based, so brush cleanup is a breeze, too!