Flatting

What the flats layer is for

Flats are not a first pass at the colours. They are a selection tool that looks like colours. Every discrete region — this sleeve, that hair, that wall — gets its own flat, hard-edged, fully opaque area. Once that exists, a colourist can click any region with the magic wand and instantly have a perfect selection to shade inside, for the rest of the book.

This is why the flats themselves are often garish. Some studios flat in deliberately hideous, maximally distinct hues so that adjacent regions can never be confused, then recolour the whole layer in one pass afterwards.

Two properties are non-negotiable:

• No anti-aliasing. Soft edges mean the wand selection leaks or leaves a halo. Flats are drawn with a hard-edged tool, aliased.
• No gaps. Every pixel under the art belongs to exactly one flat. A single unfilled pixel between two regions is a leak waiting to happen.

Why studios split it off

Flatting is slow, entirely mechanical, and requires no colour judgement whatsoever. Rendering is fast, creative and requires an experienced eye. Separating them means the expensive colourist never spends three hours lassoing hair, and — because flatting needs nothing from the rendering stage — several pages can be flatted in parallel while earlier pages are being rendered.

It is a genuine entry route into the industry: flatting is often the first paid comics job someone gets, and it teaches an enormous amount about how inking is constructed, because you see exactly where every contour fails to close.

Doing it faster

1. Close the line art first. Gap-closing is an inking responsibility. If holes exist, patch them on a separate layer above the inks rather than editing the art.
2. Work below the line art, on a layer set behind it, so the ink stays crisp on top.
3. Lasso, then fill. For hair and complex shapes the polygonal lasso is faster than chasing the wand; fill inside the selection and clean the boundary once.
4. Expand every fill by 1–2 px under the line art. Filling exactly to the edge leaves white fringing when the ink layer is later thinned or the image is scaled.
5. Flat the largest area last and simply fill everything remaining — the background is usually whatever is left.

When you can skip it

On a solo project with soft, painterly rendering and no hard region boundaries, flats buy little. They pay for themselves when there is a team, when the same characters recur across many panels with a fixed palette, or when the work is long-form colour — a webtoon series with weekly episodes is precisely the case flatting was invented for.