18 Pack Dual Brush Calligraphy Marker Pens I love to doodle~draw and color in the adult coloring books. So when these markers arrived I was really excited to try them out! Each one has a dual brush,so you can use them for a bold or thin look. The colors are very bright and they dry really quick. And they are made Acid-Free and Non-Toxic so they are safe for everyone to use. The tops go on very tight~so you will not have to worry about them drying up. They come in a nice clear case that keeps that all together when not is use. My grandchildren have used these as well and they loved them too! As the fine side made it easier for them to color in their books. You can see for yourself right here on Amazon and read all about them!