I'm getting into digital art, and I want to make a pair of twins. Because I suck at making things the same, I think the Duplicate Brush is what I need. But how do I find and use it? This was the original question. How to use the duplicate brush in Krita
It's called the Clone Brush in the newest version of Krita. To use it, do the following:
Click on the Brush Tool, then in the tool options along the top click on the brush icon, then open the presets in the side panel (there's a little arrow at the left side to open it)
Click on the Brush Engine selector, and choose Clone. Then click on the Clone Tool to select it
Resize the brush as required using the [ and ] keys
CTRL+Alt+click on the image to set the source - it will be set under X in the circle.
Paint on the image to clone it