How to Lock Lines in Procreate?

To lock lines (linework) in Procreate and prevent accidentally painting over them while allowing you to recolor or add details within their boundaries, you use Alpha Lock.

Here's how to use Alpha Lock to lock your lines:

1. Select the Layer: Tap on the layer containing the lines you want to lock. This will highlight the layer in the Layers panel.
2. Open Layer Options: Tap on the selected layer again to open the Layer Options menu.
3. Apply Alpha Lock: In the Layer Options menu, tap on "Alpha Lock."

Now, only the opaque (filled) areas of that layer will be affected by any painting or editing you do. The transparent areas around the lines are "locked," preventing you from coloring outside them. This effectively locks the lines.

How Alpha Lock Works:

Alpha Lock respects the existing alpha (transparency) of the layer. If a pixel is already transparent, Alpha Lock prevents any color from being applied to it. If a pixel is opaque, you can still change its color. This lets you recolor the linework itself or add shading within the lines without affecting the surrounding transparent areas.

Alternative Method: Clipping Mask

While Alpha Lock directly locks a single layer, a Clipping Mask provides another way to contain your painting within a specific shape, including your lines.

1. Create a New Layer: Add a new layer above the layer with your linework.
2. Create Clipping Mask: Tap on the new layer, then tap "Clipping Mask" in the Layer Options menu.

The new layer is now "clipped" to the layer below. Anything you paint on the clipping mask layer will only be visible within the opaque areas of the layer below it (your linework). This is non-destructive editing, since your linework layer is untouched.

Summary:

Feature	Alpha Lock	Clipping Mask
Affects	The selected layer directly.	A new layer, clipped to the layer below.
Functionality	Locks transparency, allows recoloring pixels.	Limits painting to the opaque areas of the layer below.
Destructive	Potentially, as it directly alters the layer.	Non-destructive, as it uses a separate layer.

Both Alpha Lock and Clipping Masks are useful tools for keeping your lines clean and allowing you to easily add color and detail within them. Choosing the best method depends on the specific task and your preferred workflow.