There’s not much difference because both can help you achieve the same result: sulky lips, with more or less pronounced colors. Water-based lip tints are more watery and they need to be layered to get a vivid color; stains, on the other side, are more pigmented and you need only one layer to get the perfect coverage. With water-based lip tints, you can create a natural-looking color without too much effort while with velvety lip stains you can get the same result by applying less product and blend it with your fingers.