History Brush and Art History Brush in Paint by Zaweba

Undo is all or nothing: it takes the whole picture back a step. The History Brush is selective. It paints back the image as it was at an earlier moment, only where you brush, so you can keep an edit in one place and remove it in another without any masks or extra layers.

In Paint by Zaweba it lives in the Y slot of the toolbar alongside its odd but entertaining relative, the Art History Brush.

Setting the source

Both brushes paint from a history state that you choose in the History panel. Each state has a marker beside it; click the marker next to the state you want to use as the source. It might be the original image as opened, or a point in the middle of your edit, such as just before you ran a strong filter.

Then pick up the History Brush and paint. Wherever you brush, the picture returns to how it looked at that state. Your current edit stays everywhere else.

Jobs for the History Brush

Selective filters. Run a sharpen or a blur on the whole image, set the marker to the state before it, and brush the original back where the effect isn't wanted. Sharpen a portrait, then paint smooth skin back from before the sharpening.

Black and white with a splash of colour. Convert to black and white, set the marker on the colour state, and paint the colour back into one object.

Recovering overcooked areas. If an adjustment blew out a sky but helped the foreground, paint the sky back from the earlier state.

Undoing a slip. When you notice a mistake several steps back but want to keep the work since, paint just the damaged area back from before it happened.

Use low opacity for gradual blends. A few soft passes at low opacity mix the old and new versions smoothly, which looks far more natural than a hard boundary.

The Art History Brush

The Art History Brush also paints from the chosen history state, but instead of reproducing it faithfully, it makes stylised strokes based on its colours. Each dab sends out several strokes that follow the colours and shapes of the source, so a photograph becomes something that looks painted.

It offers nine styles that change the shape and length of the strokes, from tight to loose and curly. The area setting controls how far each dab spreads, and the tolerance limits where strokes can land by how different the picture there is from the source, which helps keep strokes in areas that need them.

Results depend a lot on brush size. Start with a large brush over a filled layer for a rough base, then use smaller brushes and a tighter style over the important areas, such as faces and edges, to bring back detail. Varying the size gives the picture a sense of focus, as a painter would.

Practical tips

History is memory, and a long session builds up many states. If you know you will want to paint back from a particular point, consider duplicating the layer at that moment as well, so you have a copy that can't scroll out of reach.

Remember that the brushes work on the current layer. If you paint back from a state where the layer looked different or didn't exist, the result can be surprising. Keep it simple: use them on a single layer you've been editing.

For edits you might want to change later, masks on adjustment layers remain the more flexible route. The History Brush is quicker for one-off touches, and in Paint by Zaweba it pairs naturally with the Erase to history option on the Eraser, which does the same job from a different tool.