Pen pressure affects line opacity instead of thickness.
![](http://assets.clip-studio.com/en-us/description/2023108/img/d57d0668dd-3244-009a-037a-badb01fe69.png)
Using this pen with a smaller px is good for messy first-pass sketching with lots of layering.
Using this pen with a larger px is good for building up shadows in sketches
Smooth lines and consistent width make for a softer lineart.
Lots of pressure needed to reach 100% opacity