笔刷技巧：轮廓线

问题

How to make an outline for a single brush stroke using Krita?

Not really a brush, but what you can do is add a layer style to a layer, by a layer and selecting layer style. Then input the following settings:

Then, set the main layer to multiply (or add a 颜色转为透明度 filter mask), and paint with white:

(The white thing is the pop-up that you see as you hover over the layer.)

Merge into a empty clear layer after ward to fix all the effects.