Paint by hand.

The Brush is a round cursor with a radius you set. Drag it across the model and every triangle under the ring takes the active palette colour. By default it doesn't care about parts or seams — wherever the ring touches, paint lands.

That makes it the freehand tool. Reach for it on busts, dragons and terrain where there's no clean part for Magic Fill to flood, and for small irregular bits — an eye dot, a rune, a sliver another tool missed — that no automatic fill would isolate.

Hold Shift while you drag to erase instead: the brush lifts colour back to unpainted.

• Organic models — busts, animals, terrain — with no clean parts for Magic Fill to grab.
• Touch-ups — fix a stray triangle or a missed sliver after another tool.
• Freehand details — eyes, runes, decals, anything that doesn't follow the geometry.
• Recesses and raised faces — engraved text, scale tops — with Fine detail on (below).

1. Switch to Brush — the second tool on the left rail. The cursor becomes a round ring.
2. Set the radius. Drag the Radius slider in the right panel, tap [ / ], or hold Ctrl and scroll. About a coin's width on screen suits most work.
3. Drag across the surface. Every triangle under the ring takes the active colour.
4. Switch colour mid-stroke. Press 1–9 to pick a palette slot, then drag again.
5. Erase. Hold Shift and drag — the brush lifts colour back to unpainted.

All the brush's controls live in the right panel while Brush is active. Tap the ⓘ toggle at the top of the panel for a one-line explanation of each.

Tick Fine detail (aligned faces only) and the brush stops painting everything under the ring. Now it paints only faces pointing the same way as the one you first clicked. Click a flat anchor face — that locks the surface direction — then drag.

• Engraved text or runes — click inside the recess, drag, only the recessed walls colour.
• Scale or shingle tops — click one top, drag across many, the angled sides stay grey.
• A flat plate beside curved geometry — click the plate, the curve keeps its colour.

Normal tolerance (default 25°) sets how close a face's direction has to match. Tighten it to about 10° for picky work; loosen it to 60° to catch more variation. Re-anchor any time by clicking a different face. This is the old Detail tool, folded into the Brush.

Drag a brush wider than an antenna and you paint the back of it too. Depth cap stops that. At 100% the brush colours anything inside the ring, including the far side of a thin wall. Drop it and the brush only reaches the surface it's actually touching.

Lower it to about 30% for antennae, blades, fins and skirts, then orbit round to check the back stayed clean. If coverage goes dotty on a chunky surface, the cap's too low — raise it. It's a max depth, not a hard plane, and it stays where you left it.

This is the part that sets the Brush apart. A border you've drawn is a hard wall:

• The brush won't cross it. Drag right up to a border and the stroke stops dead at the line — no bleed into the colour on the far side, even with a fat ring.
• When a border encloses your stroke, the brush paints through the wall — it colours the front face and the matching back face at once, so a panel comes out solid front and back in a single pass.

That's the opposite job from Depth cap. Depth cap guards against accidental bleed through a thin wall; a containing border deliberately fills both sides.

Two more guards for tidy seams, both in the right panel:

• Stop at colour change — the stroke refuses to overwrite a different palette colour. It anchors on the first face you click, so start cleanly inside the colour you want to keep.
• Stop at crease — the stroke won't cross an edge sharper than Sharp above (default 20°). Lower that angle to stop at even gentle ridges; raise it to 40–60° so only hard edges count.

• Prefer Magic Fill when it works. If one tap of Magic Fill grabs the shape you want, use that — it's faster and lands cleaner. Reach for the Brush when there's nothing clean to flood.
• Stroke overwriting the wrong colour? Turn on Stop at colour change, and start the stroke cleanly inside the colour you want to defend.
• Paint bleeding to the back of a thin wall? That's depth, not a border — drop the Depth cap.
• Fine detail painting too much? Tighten Normal tolerance, or anchor on a flatter face.
• Jittery on a huge mesh? Normal at very high triangle counts — shrink the ring, or simplify the mesh first.