This is my favorite white gel pen and a part of my nature journaling kit. I use it to draw white lines on toned paper and to add highlights and details over dry watercolor, such as that dot of light that can bring a bird eye to life or the sunlight highlights on water. This pen is also water soluble, so you can lighten or it or “erase” it with a damp brush. I also love that, once the pen line is dry, you can tint the lines different colors with watercolor. For instance, you could draw a leaf, paint it dark green, let it dry, draw in leaf veins with the gel pen, feather and fade those lines with a damp brush if desired, and then, once the gel pen is dry, you can go back and tint those lines light green with watercolor.