The Smart Pen Calibration function allows you to regulate the width and sharpness of your handwriting on screen depending on the amount of pressure you typically apply when writing on the page. Move the slider in the Pen Calibration graph so that your handwriting appears thicker or thinner based on your unique writing style.
If you have already registered your Smart Pen, you can explore this function by clicking on the pen icon on the top right of the app page, then going to the calibration section