Have you ever wished you could shade or draw inside of a shape’s boundaries without going outside of the lines?
The Procreate app has a few different ways to to make sure you paint only within the boundaries of a shape.
One of the easiest way to do this is to use the alpha lock feature in Procreate.
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Alpha lock is a function that you can turn on in the layers menu that makes it so that you can only draw on the pixels that already have something on them within a base layer.
In other words, if you draw and color in the shape of a circle, and use alpha lock on the layer, you’ll only be able to color or create marks on the circle. You will not be able to create any marks outside of that circle.
What’s The Alpha Lock Feature Used For?
There are several things you can use alpha lock for.
Here are some examples:
- Shade an object
- Change the color of the line drawing
- Change the layer’s fill colors
- Add textures
- Add a pattern
- Add doodles or other decorations
- Fill a layer
How to Use Alpha Lock in Procreate
There are two ways to use alpha lock in Procreate.
The first way is to open your layer panel by going to your layers icon, then clicking on the title of layer that you want to use alpha lock on. A fly-out menu comes up. Click on alpha lock within that layer.
On that layer you’ll see a checkerboard pattern on the layer thumbnail in the layer panel. This means that alpha lock is on.
Another way to use alpha lock is to use the alpha lock shortcut The shortcut for turning alpha lock on and off on a layer is to take two fingers and slide them to the right on the layer in the layer menu.
You can also turn off alpha lock in the same way.
What’s The Difference Between Alpha Lock and Clipping Mask
The difference between clipping mask and alpha lock is that clipping mask is done on a different layer than your original drawing, while alpha lock is done on the same layer.
This means that when you use clipping mask, you aren’t actually changing your original layer. A clipping mask allows you to change the illustration in a non-destructive way.
You can easily change things back or even make multiple versions that you can turn on and off. Since you’re making changes to a clipping mask layer instead of on the original layer, you can easily fix any mistakes you make.
To use a clipping mask, create an additional layer on top of the layer you want to make changes to. Click on the title of the new layer and then select clipping mask in the flyout menu.
This will create a little arrow on your layers panel that shows that the layer is clipped to the one below it.
You can create multiple clipped layers and make each change on a separate layer.
When using alpha lock, you are changing the color of the pixels on the layer so the only way to go back is to undo or to start over.
But in clipping mask, you are able to turn off the clipping mask to see what you did outside of the mask.
You can also turn off the layer altogether, removing the stuff you added to the mask.
Pros and Cons of Using Alpha Lock
The biggest pro to using alpha lock over other options is that you use less layers with alpha lock since everything is done on the same layer. If you have a newer 2021 iPad Pro with 1TB or higher, you don’t have to worry about layer amounts.
I also use alpha lock frequently when I want to change the color of the entire layer.
While alpha lock is super convenient, there are some things to keep in mind when choosing whether to use it.
The most important thing to remember is that you’re drawing on the actual layer and your new marks are not separate from what you already drew. This makes it harder to edit your drawing. If you want to make your line thinner for example, you won’t be able to just erase the line without also erasing what is underneath it.
I’ve been frustrated many times by this. I draw something on a layer, go to erase part of it and it erases everything underneath it as well. In the next picture, I’ll show you what I mean by trying to make the line on my heart a dotted line.
Instead of showing pink behind the line, I erased the heart as well:
Thank goodness for the undo feature in Procreate! (2 fingers tapped on the screen).
If I wanted to change just the green line, I would use clipping mask instead:
It’s also more difficult to adjust the colors of the drawing after the fact when using alpha lock. I tend to use alpha lock only for less complex illustrations or for changing the entire layer to a different color. I also may use alpha lock if I’m trying to quickly add a shadow to part of my illustration; however, I’m more likely to do that using a different type of mask.