Opacity and blending
What applies to the whole object

The sun at 80% with the screen blend mode over the mountains, with Opacity and Blend at the bottom of the panel

At the bottom of the panel

Opacity and blending do not belong to a paint: they apply to everything the object draws, fill and stroke included.

FieldWhat it does
Opacityfrom 0 to 100, as a percentage
Blendhow the object blends with what lies beneath it: normal, multiply, screen, overlay, darken, lighten, color dodge, color burn, hard light, soft light, difference, exclusion, hue, saturation, color, luminosity