SUMMARY: Using Krita with an XP-Pen Star 03 tablet. When using the tablet with Krita, only one weight of the line is produced and "tics" and ghost lines" appear. STEPS TO REPRODUCE 1. Vertical lines with XP-Pen diagnostic app = No issues with the tablet. 2. Vertical lines on Krita = Heavy lines with tics and ghost lines. 3. Vertical lines on a competitor of Krita = No problems. OBSERVED RESULT Heavy lines, no response to pressure sensitivity, and tics and "ghost lines" EXPECTED RESULT Clean lines that respond to pressure sensitivity. SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: (available in About System) KDE Plasma Version: KDE Frameworks Version: Qt Version: ADDITIONAL INFORMATION I would prefer to use Krita if I can get it to work with my tablet. The evidence indicates to me that the problem is not the tablet, but how it interfaces with Krita.
The problem likely is in the tablet driver. You could try to update the driver; reset the driver's settings. You can also try to reset Krita's settings (https://docs.krita.org/en/KritaFAQ.html#resetting-krita-configuration) or switch between Wintab and Windows 8 Pointer API in the tablet settings page in Krita's settings dialog. I often hear from people with XP-Pen tablets that they have problems, but we know we've implemented support for both API's correctly... But drivers often have special-casing for applications, and are often only tested with a few applications, like Photoshop, and may give the impression that everything is fine, even if the drivers are buggy... There isn't anything we can do... We don't have XP-Pen hardware and contacting the tablet manufacturer seldom works, because the software developers who create the drivers often only speak Chinese and are convinced in any case the problem is on their side :-(