To color only inside the lines in Procreate, restrict your paint to a defined area before you start brushing. You can do that three ways: Alpha Lock on a layer that already holds a base fill, a Clipping Mask attached to a filled shape, or an Automatic selection of the area you want to paint. For line art, the most reliable setup is to mark the line layer as Reference, ColorDrop a flat base color on a layer beneath it, then Alpha Lock or clip that layer and paint freely.

Pick the right method first

Each method keeps color inside a boundary, but they differ in how editable the result is. Choose based on what you'll need to change later.

Method 1: Reference layer, ColorDrop, and Alpha Lock

This is the standard approach for inked drawings, and it works well when you want clean flats and then shading on top.

1. Set your line art as Reference. Tap the line art layer and choose Reference. Procreate will now treat that layer as the boundary for fills, even when you're working on a different layer.
2. Add a new layer for color. Keep it separate from the line art.
3. ColorDrop into the shape. Drag a color from the color swatch into the enclosed area. Because the line layer is the Reference, the fill stops at the lines.
4. Turn on Alpha Lock for the color layer by swiping right on it with two fingers (a checkerboard appears on the thumbnail). Everything you paint will now land only on pixels that already have color.
5. Paint your shading. Gradients, textures, and soft brushes won't spill past the edges of the base fill.

Repeat on a new layer for each area, such as skin, clothing, or background. A separate layer per region makes later changes trivial: Alpha Lock lets you recolor an entire region in one pass without redrawing it.

Closing gaps

ColorDrop only works as a boundary if the shape is fully closed. If color floods the whole canvas, there's a gap somewhere. Zoom into the corners where strokes meet and close the gap on the line layer.

Method 2: Clipping Mask

A clipping mask is the more flexible alternative to Alpha Lock, because the paint lives on its own layer.

1. Put a solid base shape on one layer (a fill or silhouette).
2. Create a new layer above it.
3. Tap the new layer and choose Clipping Mask. The layer now shows only where the layer below has pixels.
4. Paint on the clipped layer. Nothing appears outside the base shape.

The advantage over Alpha Lock is that you can change the blend mode, opacity, or color of the clipped layer independently, or hide it entirely, without touching the base. You can stack several clipped layers (shadow, highlight, texture, rim light) on one base shape and toggle each separately. The cost is a longer layer stack, so name and group layers as you go.

Alpha Lock bakes the paint into the same layer as the base fill. That's faster and tidier for quick work, but you can't separate the shading from the flat color afterward.

Method 3: Selection tool

If you don't want to prep fills, select the area and paint within it.

Select the inside directly

1. On your canvas, tap the Selection tool (the S-shaped icon).
2. Choose Automatic and make sure only Add is on and Color Fill is off. If Color Fill is on, tapping will fill the shape with color instead of selecting it.
3. Tap inside the shape. Procreate selects the empty area enclosed by the lines.
4. Select your brush, switch to a layer beneath your line art, and paint. Strokes appear only inside the selection, and the hatched markings sit over the protected area.
5. Tap the Selection tool again to exit.

Select the outside, then invert

Instead of tapping the inside, tap the outside area and press Invert. The selection now includes the lines as well as the interior. When you paint on a layer under the line art, color extends beneath the lines. That prevents the thin, uncolored fringe that anti-aliased edges leave when you fill only up to the lines. It's especially useful if your line art uses a soft or textured brush, or if you want to change the line layer's blend mode (such as Multiply) without a gap showing through.

A common mistake is selecting the line layer's own pixels using Select on the layer, which selects the lines rather than the empty area. You want the empty pixels, so use Automatic.

Method 4: Carve color out of a shape

If you've already painted something and need only the part inside a shape, select the shape area, go to the layer with the paint, and use Copy and Paste (or Cut and Paste) to move just that portion to a new layer. This is a quick fix, but it modifies pixels. Duplicate the layer first so you can go back.

Keep your line art safe

Several habits prevent accidental damage:

• Put color below the lines whenever possible. Line art on top, color beneath, and nothing you do to color can affect the lines.
• Lock the line layer (swipe left on it and choose Lock) so a stray stroke can't land on it.
• Use Multiply on a color layer sitting above dark lines if you must paint over them. The lines stay visible.
• Name your layers. "Skin_base," "Skin_shade," and "Lines" take seconds and save minutes when you revisit a file.

Troubleshooting

Paint still goes outside the shape. Check whether Alpha Lock is actually on (look for the checkerboard thumbnail), and confirm you're painting on the correct layer. Also confirm the layer wasn't filled larger than the shape.

A thin white outline shows between color and line. The fill stopped short of the line's anti-aliased edge. Use the invert-selection method so paint goes underneath the lines.

ColorDrop fills the entire canvas. The shape has a gap, or the Reference layer isn't set. Close the gap or check the Reference setting.

Clipped layer shows nothing. The layer under it may be empty, or the clipped layer is above a different layer than you intended. Clipping applies to the layer directly below.

The selection tool fills with color instead of selecting. Turn off Color Fill in the bottom toolbar.

Moving the result into a motion pipeline

If the artwork is heading into animation, the layer structure you built matters more than the final flattened image. Export a layered file so each region (base color, shading, lines) stays on its own layer, which lets you adjust parts separately downstream. Keep the line layer at full resolution and avoid merging layers until you're sure the piece is final. For frame-by-frame work, keep a consistent naming and layer convention across frames so that you can batch-handle them downstream.

Quick recap

• Use Reference + ColorDrop + Alpha Lock for fast flats with shading that stays inside the lines.
• Use a Clipping Mask when you want shading or texture on separate, editable layers.
• Use Automatic Selection, ideally selecting the outside and inverting, when you want color under the lines or don't want to prep fills.
• Keep line art on its own locked layer, above the color.
• Export layered files if the artwork is going on to animation or compositing.

Once the layer structure is right, coloring inside the lines stops being something you manage with a steady hand and becomes something the file does for you.

To color only inside the lines in Procreate, restrict your paint to a defined area before you start brushing. You can do that three ways: Alpha Lock on a layer that already holds a base fill, a Clipping Mask attached to a filled shape, or an Automatic selection of the area you want to paint. For line art, the most reliable setup is to mark the line layer as Reference, ColorDrop a flat base color on a layer beneath it, then Alpha Lock or clip that layer and paint freely.

Pick the right method first

Each method keeps color inside a boundary, but they differ in how editable the result is. Choose based on what you'll need to change later.

Method 1: Reference layer, ColorDrop, and Alpha Lock

This is the standard approach for inked drawings, and it works well when you want clean flats and then shading on top.

1. Set your line art as Reference. Tap the line art layer and choose Reference. Procreate will now treat that layer as the boundary for fills, even when you're working on a different layer.
2. Add a new layer for color. Keep it separate from the line art.
3. ColorDrop into the shape. Drag a color from the color swatch into the enclosed area. Because the line layer is the Reference, the fill stops at the lines.
4. Turn on Alpha Lock for the color layer by swiping right on it with two fingers (a checkerboard appears on the thumbnail). Everything you paint will now land only on pixels that already have color.
5. Paint your shading. Gradients, textures, and soft brushes won't spill past the edges of the base fill.

Repeat on a new layer for each area, such as skin, clothing, or background. A separate layer per region makes later changes trivial: Alpha Lock lets you recolor an entire region in one pass without redrawing it.

Closing gaps

ColorDrop only works as a boundary if the shape is fully closed. If color floods the whole canvas, there's a gap somewhere. Zoom into the corners where strokes meet and close the gap on the line layer.

Method 2: Clipping Mask

A clipping mask is the more flexible alternative to Alpha Lock, because the paint lives on its own layer.

1. Put a solid base shape on one layer (a fill or silhouette).
2. Create a new layer above it.
3. Tap the new layer and choose Clipping Mask. The layer now shows only where the layer below has pixels.
4. Paint on the clipped layer. Nothing appears outside the base shape.

The advantage over Alpha Lock is that you can change the blend mode, opacity, or color of the clipped layer independently, or hide it entirely, without touching the base. You can stack several clipped layers (shadow, highlight, texture, rim light) on one base shape and toggle each separately. The cost is a longer layer stack, so name and group layers as you go.

Alpha Lock bakes the paint into the same layer as the base fill. That's faster and tidier for quick work, but you can't separate the shading from the flat color afterward.

Method 3: Selection tool

If you don't want to prep fills, select the area and paint within it.

Select the inside directly

1. On your canvas, tap the Selection tool (the S-shaped icon).
2. Choose Automatic and make sure only Add is on and Color Fill is off. If Color Fill is on, tapping will fill the shape with color instead of selecting it.
3. Tap inside the shape. Procreate selects the empty area enclosed by the lines.
4. Select your brush, switch to a layer beneath your line art, and paint. Strokes appear only inside the selection, and the hatched markings sit over the protected area.
5. Tap the Selection tool again to exit.

Select the outside, then invert

Instead of tapping the inside, tap the outside area and press Invert. The selection now includes the lines as well as the interior. When you paint on a layer under the line art, color extends beneath the lines. That prevents the thin, uncolored fringe that anti-aliased edges leave when you fill only up to the lines. It's especially useful if your line art uses a soft or textured brush, or if you want to change the line layer's blend mode (such as Multiply) without a gap showing through.

A common mistake is selecting the line layer's own pixels using Select on the layer, which selects the lines rather than the empty area. You want the empty pixels, so use Automatic.

Method 4: Carve color out of a shape

If you've already painted something and need only the part inside a shape, select the shape area, go to the layer with the paint, and use Copy and Paste (or Cut and Paste) to move just that portion to a new layer. This is a quick fix, but it modifies pixels. Duplicate the layer first so you can go back.

Keep your line art safe

Several habits prevent accidental damage:

• Put color below the lines whenever possible. Line art on top, color beneath, and nothing you do to color can affect the lines.
• Lock the line layer (swipe left on it and choose Lock) so a stray stroke can't land on it.
• Use Multiply on a color layer sitting above dark lines if you must paint over them. The lines stay visible.
• Name your layers. "Skin_base," "Skin_shade," and "Lines" take seconds and save minutes when you revisit a file.

Troubleshooting

Paint still goes outside the shape. Check whether Alpha Lock is actually on (look for the checkerboard thumbnail), and confirm you're painting on the correct layer. Also confirm the layer wasn't filled larger than the shape.

A thin white outline shows between color and line. The fill stopped short of the line's anti-aliased edge. Use the invert-selection method so paint goes underneath the lines.

ColorDrop fills the entire canvas. The shape has a gap, or the Reference layer isn't set. Close the gap or check the Reference setting.

Clipped layer shows nothing. The layer under it may be empty, or the clipped layer is above a different layer than you intended. Clipping applies to the layer directly below.

The selection tool fills with color instead of selecting. Turn off Color Fill in the bottom toolbar.

Moving the result into a motion pipeline

If the artwork is heading into animation, the layer structure you built matters more than the final flattened image. Export a layered file so each region (base color, shading, lines) stays on its own layer, which lets you adjust parts separately downstream. Keep the line layer at full resolution and avoid merging layers until you're sure the piece is final. For frame-by-frame work, keep a consistent naming and layer convention across frames so that you can batch-handle them downstream.

Quick recap

• Use Reference + ColorDrop + Alpha Lock for fast flats with shading that stays inside the lines.
• Use a Clipping Mask when you want shading or texture on separate, editable layers.
• Use Automatic Selection, ideally selecting the outside and inverting, when you want color under the lines or don't want to prep fills.
• Keep line art on its own locked layer, above the color.
• Export layered files if the artwork is going on to animation or compositing.

Once the layer structure is right, coloring inside the lines stops being something you manage with a steady hand and becomes something the file does for you.