The reason you get to hear so many questions about using these pens is because they are flowy. Although it has the shape and structure of a pen, you can use it like a paint brush. Before starting, you have to shake the pen to distribute the paint uniformly inside. Once done, you are now ready to do your work. While on it, you can squeeze the pen to pour more colour and create a drip effect or others as you imagine it. Many variants of paint markers are very flowy, while others are not. But the process of using them will remain the same as we stated just now.