How to remove window border drop shadow in KDE

Some KDE themes display drop shadows on the window's border. It is It is suitable for aesthetic and user experience, but there could be cases where it's not desirable, such as taking a screenshot of a window panel.

Breeze is the default KDE theme for Linux distributions such as Kubuntu. While this guide is specific to Breeze, the location and option of disabling panel shadow for other KDE themes are generally the same.

1. Launch System Settings from the Application Launcher.
2. Click on Appearance on the sidebar menu.
3. Go to Window Decorations from the sidebar menu.
4. Hover on current theme and click on Edit Theme button.
5. Click on Shadows tab.

   The panels could be different depending on the theme, and the option to change the drop shadow might not exist at all. This example is based on the Breeze theme.

6. Click on Size select list.
7. Select None to disable window border drop shadow.
8. Click OK to save and immediately apply the configuration change.