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If you‘re a digital artist using Procreate, you need to have alpha lock in your toolbox. This powerful feature can majorly level up your workflow by allowing you to edit and add to your artwork in a non-destructive way. In fact, alpha lock is one of the top 5 most used features by professional Procreate artists, according to a recent survey by Savage Interactive[^1].
As a long-time Procreate user and teacher, I‘m always surprised that alpha lock flies under the radar for many beginners. But once you understand how it works and all the ways you can use it, it‘ll become one of your most reached-for tools. In this ultimate guide, I‘ll demystify alpha lock and show you exactly how to use it to work faster and smarter in Procreate.
What is Alpha Lock?
First, let‘s break down what "alpha lock" actually means. In digital image editing, "alpha" refers to the transparency of a layer. Every layer in Procreate has a red, green, blue (RGB) color component that determines the hue and tone of the pixels, as well as an alpha component that determines the opacity of each pixel[^2].
When you draw or paint on a layer, those marks are 100% opaque, while the empty areas of the layer are 0% opaque (i.e. transparent). What alpha lock does is lock the transparency—so you can only paint within the boundaries of your existing artwork on that layer.
Essentially, alpha lock restricts your brushstrokes to the areas of the layer that already have paint on them. It‘s like putting a seal over the transparent parts of the layer. You can still move, scale, or distort the layer itself, but you can‘t add or erase outside the lines of your original art.
One important thing to note: alpha lock works on a per-layer basis. If you have multiple layers in your artwork (which you should!), you can alpha lock some while leaving others unlocked. Alpha lock also remains active on a layer until you manually turn it off—simply switching to a different layer won‘t disengage the lock.
How to Use Alpha Lock in Procreate
Activating alpha lock on a layer in Procreate is easy and intuitive. Here‘s how to do it:
- Open the Layers panel by tapping the stacked squares icon
- Select the layer you want to lock by tapping its thumbnail
- Tap the "Alpha Lock" button in the layer options menu
You‘ll know alpha lock is turned on when you see a checkered transparency pattern appear on the layer thumbnail. To turn it off, simply tap the layer thumbnail and toggle off "Alpha Lock" in the menu.
Pro tip: Use a two-finger horizontal swipe on the layer thumbnail as a shortcut to quickly toggle alpha lock on and off.
Alpha Lock Use Cases
Now that you know the mechanics of how alpha lock works, let‘s dive into some practical examples and use cases. Here are XX ways you can incorporate alpha lock into your Procreate workflow to work more efficiently:
1. Coloring Inside the Lines
One of the most common uses for alpha lock is filling in line art or sketches with color. With alpha lock turned on, you can color inside the lines without having to worry about your brushstrokes going outside the boundaries.
Here‘s a basic coloring workflow using alpha lock:
- Create your line art on one layer
- Activate alpha lock on the line art layer
- Add a new layer underneath for your colors
- Use the brush tool to color the line art—your brushstrokes will only fill the areas inside the lines
This is a great way to quickly lay down flat colors for an illustration without having to be precious about staying inside the lines. You can even use textured or patterned brushes to add interest to your coloring.
2. Trying New Color Schemes
In addition to coloring line art, alpha lock is super useful for experimenting with different color schemes and palettes. Since the alpha locked layer will constrain your brushstrokes to the existing areas of color, you can easily swap hues without affecting the original composition.
For example, let‘s say you painted a portrait and you want to try out some different hair colors. Here‘s what you could do:
- Isolate the hair on its own layer
- Alpha lock the hair layer
- Use the eyedropper tool to sample the base hair color
- Open the color panel and adjust the HSB sliders to change the hair color
- Paint over the hair—the new color will only replace the area of the original hair color
Repeat this process to audition as many different hair colors as you want. Using alpha lock in this way is an excellent method for finessing your color choices without having to repaint the entire portrait each time.
3. Adding Texture and Shading
Alpha lock is also invaluable for adding details and dimension to a piece without altering the base colors or shapes. With alpha lock on, you can add textures, shadows, and highlights while keeping them constrained to your original artwork.
For example, imagine you‘ve blocked in a simple shape for a tree canopy. Here‘s how you could use alpha lock to turn that basic shape into a more realistic tree:
- Alpha lock the canopy layer
- Choose a texture brush like "Vegetation" or "Foliage"
- Sample a darker shade of the canopy color for shadows
- Paint shadows along the bottom edge and in spots throughout the canopy
- Sample a lighter highlight color
- Paint highlights on the top edges and spots where light would hit
By utilizing alpha lock, you‘re able to work loosely with textured brushes without worrying about painting outside the original shape. This allows you to transform flat, basic shapes into objects with realistic form and volume.
You can also use alpha lock with layer blend modes like Multiply or Overlay to create dimensional shading and lighting effects. Simply alpha lock your base layer, create a new layer above it, and set the blend mode to alter the base color.
4. Creating Masks and Stencils
Alpha lock can function as a built-in masking system for your layers. By locking the transparency of a layer, you‘re effectively creating a mask that allows you to paint within—but not exceed—the bounds of your artwork.
You can even use alpha lock to create stencils and templates for repeated design elements. Let‘s say you want to create a polka dot pattern:
- On a new layer, paint a single circle with a basic brush
- Alpha lock the layer with the circle
- Use the "Fill Layer" option to turn the circle a solid color
- Duplicate the circle layer multiple times
- Arrange the duplicated circles into a pattern
- Merge the circle layers together into a single polka dot stencil layer
Now you can alpha lock the polka dot stencil layer and use it as a template for filling in different colors and textures while maintaining the pattern. You could even use the stencil layer as a clipping mask for other patterned layers.
Alpha Lock vs. Clipping Masks vs. Layer Masks
If you‘re familiar with clipping masks and layer masks, you might be wondering how alpha lock compares. While all three have some similarities in terms of constraining your edits to certain areas, there are distinct differences in how they function.
Here‘s a quick breakdown of each:
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Alpha Lock: Locks the transparency of a single layer so you can only paint within the existing areas of color on that layer. Best for making direct edits to a layer.
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Clipping Masks: Uses the content and transparency of a bottom layer to mask and constrain any layers clipped above it. Allows you to non-destructively clip multiple layers to the bottom masking layer.
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Layer Masks: Creates an additional black and white "mask" that controls the transparency of the layer it‘s attached to. Painting black on the mask conceals portions of the masked layer, while white reveals. Provides more manual control over transparency.
In general, alpha lock is best for quickly locking off a single layer to make direct edits, while clipping and layer masks are better for building up an illustration non-destructively with multiple layers. Clipping masks are great for keeping your layers organized in parent-child relationships, while layer masks are ideal for blending and fading effects.
Tips for Using Alpha Lock
To wrap up, here are some tips and best practices to keep in mind when using alpha lock in Procreate:
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If an alpha locked layer isn‘t working as expected, check that you don‘t have a clipping mask or layer mask applied to it as well, as those can affect the behavior of alpha lock.
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When filling an alpha locked layer with color or texture, tap the layer first before painting to "set" your fill. This will give you a hard edge around your artwork.
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Remember you can erase on an alpha locked layer to punch out areas of transparency.
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Use alpha lock in combination with reference layers and drawing guides for foolproof sketching and inking.
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If you want to alpha lock multiple layers at once, create a layer group, select it, and choose "Alpha Lock Group" from the group options menu.
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Don‘t forget about the two-finger swipe shortcut for quickly toggling alpha lock on the selected layer!
I hope this guide has given you a solid understanding of how to use alpha lock in Procreate to upgrade your digital art workflow. Incorporate alpha lock into your next project and see how much time and effort it can save you.
Have other tips for using alpha lock? Share them in the comments below! Happy alpha locking!
[^1]: "Procreate 2022 Year in Review," Savage Interactive, accessed February 28, 2023, https://procreate.art/yearinreview
[^2]: "The Ultimate Guide to Digital Painting in Procreate," 3DTotal Publishing, accessed February 28, 2023, https://shop.3dtotal.com/collections/digital-painting/products/the-ultimate-guide-to-digital-painting-in-procreate