A coloring marker for painting.
A marker/paintbrush-ish? thing! I wanted something that you can build up layers with delicately, so here's what came out!

To the left, a picture of the King in Yellow (a character from Robert Chamber's 1895 public domain novel of the same name) almost entirely made with the brush (the crown was made with my sketchbrush). The right, a few scribbles showing the brush at different pressures. I like using it at larger sizes, but it can do smaller details like the cloak's embrodery thanks to it's smooth edge. It's great for covering big areas and the oval shape makes it handy for corner areas as well. Feel free to adjust the brush's settings
to your liking!

The blue box shows it's blending and opacity. The top scribble in the box is a single stroke, the bottom scribble is multiple strokes with the color picker. It gives a gentle streaky finish this way, but can be made even smoother with patience. The middle is a single stroke across two colors.
I think this brush does well at soft rendering - the boat on the right is all hard edges, but has a soft, smooth, plastic look thanks to the brush's settings. I suggest it for skin & other smooth surfaces.

Lastly, while this brush was meant to be used for long, slow sessions, it can be used for speed painting like the picture above (1 hour). It's up to you!
Thanks for reading, I hope you find this brush helpful! :)