The Blur, Sharpen and Smudge brushes in Paint by Zaweba

Filters change a whole layer or selection at once. Sometimes you only want a touch of softness on one edge, or a little crispness on one eye. The Blur and Sharpen tools in Paint by Zaweba are brushes that paint those effects where you put them, and the Smudge tool, their close relation, pushes paint around as if with a finger.

Blur

The Blur tool softens whatever you brush over. It uses the brush engine, so size, hardness and pressure all shape the stroke, and repeated passes build up the effect.

Photographers use it to soften a distracting edge, take the harshness off a stray hair against the background, or blend a hard join in a composite. Painters use it to push background areas out of focus so the subject stands forward. A soft brush at low strength, used in several passes, gives the most natural result.

For blurring large areas, a selection and a blur filter is quicker and more even. Keep the brush for small, targeted touches.

Sharpen

The Sharpen tool increases edge contrast where you paint. Its protect detail option keeps the effect from turning fine texture into noise and stops sharpened areas getting gritty, so it is worth leaving on for photos.

The classic use is eyes in a portrait. Sharpen the irises and lashes a touch and the face comes to life, while the skin stays soft. It also helps with jewellery, the text on a product label, or any small part of a picture that needs to draw the eye.

Go lightly. Over-sharpened areas show bright halos along edges and look crunchy. Several gentle strokes beat one strong one, and zooming out to normal viewing size shows whether the effect looks real.

Smudge

Smudge picks up the colour where a stroke starts and drags it along, like a finger through wet paint. It is the painter's blending tool: softening the transition between two colours, pulling wisps of hair out of a head, streaking clouds, or adding motion to an edge.

Finger painting is an option that starts each stroke with the foreground colour, as if your finger had been dipped in paint first, then smears it into what is already there. It is handy for adding colour and blending in one movement.

Pigment mixing makes Smudge blend more like real paint. Mixing colours on screen in the usual way can give greyish, muddy results between complementary colours; pigment mixing follows how physical paints combine, so yellow and blue give a green rather than a grey. For digital painters working in a traditional style this makes Smudge feel much more natural.

Brush choice matters

All three tools use the brush tips from the shared brush engine. A textured tip on Smudge gives a dry, bristly blend, while a soft round tip gives a smooth one. For Blur and Sharpen, softer tips make the edge of the effect invisible.

Setting up a few tool presets saves time: a gentle soft blur, a light sharpen for eyes, a textured smudge for blending paint. Tool presets in Paint by Zaweba save the tool's options and brush together under one name.

Working safely

These tools change pixels directly. When retouching photos, work on a duplicate layer so you can compare and dial the effect back with opacity. Some photographers prefer to sharpen on a separate merged copy at the very end of an edit, after resizing, since sharpening needs depend on the final size.

When painting, remember that Smudge works on the layer you are on. If the colours you want to blend sit on several layers, merge them first or the smudge will only drag one of them.

These are small tools with a big effect when used carefully. A minute with Sharpen on the eyes, Blur on a distracting edge and Smudge on a hard paint join often finishes a picture better than any filter.