Brush tool

Paint with pressure-sensitive brushes on pixel layers, or lay down crisp filled vector strokes on a Shape layer.

The Brush tool paints on whichever layer is selected, and what it produces depends on the type of that layer. On a Raster or Pixel layer you get pixels; on a Shape or Drawing layer you get real vector geometry with a crisp outline you can still edit afterwards.

Press B to reach the Brush. Colour comes from the Color panel: the brush uses the active colour slot at the moment the stroke starts, so switching colours mid-stroke has no effect until the next one.

Which layer the brush paints on#

• Raster or Pixel layer: paints pixels into the layer's cell for the current frame.
• Shape or Drawing layer: paints vector blobs (see below).
• Any other layer, or nothing selected: paints pixels, or vector, depending on the New Layer option; on the first stroke it creates the layer you chose.
• A locked or hidden paintable layer: nothing is painted. The canvas shows the banner "No paintable layer active. Select or add a Raster/Vector layer." for two seconds.

The options bar#

The bar opens with the tip swatch, the preset combo and the Brush Studio button, then the four numbers you reach for while painting. Size, Opacity and Flow belong to the preset and are saved with it, so changing them edits the brush you have selected rather than a temporary tool setting.

The chevron at the end opens the settings you set once and then leave: Symmetry, Draw Into and New Layer. A dot on the chevron means something inside it is off its default, so a symmetry you turned on last week cannot silently change every stroke.

The cursor#

The tip is drawn as its own silhouette, the way Photoshop does it, so a chisel, spatter or foliage nib is recognisable before you lay down a single dab. Holes and separate islands in the tip come through as well, and the outline is squashed and turned by the preset's own Roundness and Angle. A preset with no bitmap tip, the procedural soft disc, stays a plain circle, which is exactly what it paints.

Around it, a second circle shows the full footprint including scatter and size jitter. That one stays a circle by definition: it is the reach of the jitter, not the shape of the nib, and it only appears when it is meaningfully bigger than the tip. Both are grey normally and red whenever Eraser is on.

Pressure and tilt#

A graphics tablet feeds pressure and tilt into every point of the stroke, and the preset decides what they drive: size, opacity or any other dynamic. With a mouse, pressure is always full.

Painting on a Shape or Drawing layer#

On these layers the brush is a vector blob brush: the blue preview you drag is the exact region that will be added, mirrored copies included. On release the region is merged into the target shape as one compound shape, so overlapping strokes become a single clean silhouette rather than a stack of outlines.

On a Shape layer the target is simply the shape you have selected, however it was drawn. Painting on a rectangle, or on a path you made with the Pen, welds the stroke into that same path: what you get is one outline around the combined silhouette, not the stroke sitting on top of the old edge. The layer keeps its transform, its keyframes and its effects, so an animated shape carries on animating. Only when nothing usable is selected does a stroke create a shape of its own.

A stroke that lands away from the shape cannot be welded to it, so it stays a separate closed outline inside the same layer, and a stroke that loops around empty space leaves that space as a hole. Both are what the merge should do; painting across the gap afterwards joins them into one outline.

The merge is a true boolean union in exact integer arithmetic: it never moves a point of your outline, it only adds the intersections. Its fill rule is switched to non-zero so crossing strokes add up instead of cutting holes, and a shape that had no fill takes the brush colour as its fill, which means a path drawn as an outline only comes out filled. Keep a copy of a shape you still want to edit by its original handles.

The union writes polygon rings, so the result is refitted as bezier curves before you ever see it. Nodes land only where the neighbouring handles can carry the curve, genuine corners are found and pinned Sharp, and a painted stroke comes back as a handful of curves rather than the thousand-odd anchors the raw union would have left. The error budget is derived from the brush radius and clamped well under a pixel, and the fit refuses to run at all once it would cost a shape more than a fraction of its own diagonal, so a hairline stroke is never eaten by its own smoothing. Press Simplify on the Node tool when you want fewer points still.

The tip shapes the stroke#

A preset with a real bitmap tip stamps that tip's outline along the path and unions the stamps, so a chisel or a flat nib leaves a vector stroke with the same silhouette the cursor showed and the raster brush would have painted. A preset with no tip is the procedural soft disc, which is a round offset by definition, so those keep the faster round-offset path and come out identical either way.

What the vector side stamps is the tip's envelope, not its every speckle: islands and specks are dropped and the outline is held to a couple of dozen points. Per-bristle grain is a raster property, and a rough nib's true silhouette is a fractal edge that no editable path can carry. The envelope keeps what vector can express, a chisel, an oval, a flat or a blob, and leaves the texture to the pixel side.

Colour is the one thing that still starts a new shape: a path can hold exactly one fill, so paint merges only into a shape whose fill already matches your active colour, or into one with no fill at all. Paint a different colour and you get a new shape instead of having the old one repainted.

With Eraser on, the same region is subtracted instead. Erasing a shape away completely removes it.

On a Drawing layer the brush works per cell and has to find its own target, so there it merges only into shapes an earlier brush stroke made, and only when their fill colour matches your active colour. Line art you drew on the cell with the Pen or the Pencil is never absorbed, and picking a different colour starts a new shape, which is what keeps line and fill separable on the same cell.

Presets and Brush Studio#

The combo at the left of the options bar picks the active preset and previews each one as a stroke thumbnail. The full preset library, with categories and the right-click New, Duplicate and Delete commands, lives in the Brushes panel; every parameter of the active preset is edited in Brush Studio, which the icon button beside the combo opens. Both have their own pages.

The tip swatch sits beside that pair and opens the tip popup: the tip shape grid, Tip Angle, Angle Jitter, Scatter and Direction Follow. It edits the active preset rather than holding tool-local values, so what you set here is what the preset paints with everywhere. The Pencil, Eraser and Smudge bars carry the same popup.

The Brush keeps its own preset, separate from the ones the Pencil, Eraser and Smudge remember, and it survives closing the app. Coming back to the Brush restores its card and jumps the Brushes panel to the matching family. The Brush draws from the whole library, so no category is off limits to it.

Working with selections and snapping#

When a pixel selection is live, the stroke is clipped to it, and clipped live: paint stops at the marching ants while you draw rather than spilling over and snapping back when you lift the pen. This holds on both sides of the tool, the raster stroke and the vector blob, so painting inside a selection behaves the same whatever kind of layer you are on. With snapping on, Snap to Grid enabled and the grid visible, brush input is snapped to the grid as you draw.