{27 Questions Solved}
How To Use Layers In GIMP

This is the second in a series of articles on how to use layers in GIMP. Previously, we discovered what layers are, how to access them, the four kinds of layers, 4 ways to customize them, and more.

Today, I’m going to answer the 27 most questions I get about using layers in GIMP. So, get ready to mark those questions {Solved}!

In case you missed the other “how-to” layer guides, here they are…

GIMP Layers 101 {the Complete Guide}
How To Use a Layer Mask In GIMP: Like a Pro {Complete Guide}
Advanced GIMP Layer: the Alpha Channel {Complete Guide}
How To Use Blending Modes In GIMP {Complete Guide}
How To Align Layers In GIMP {Complete Guide}
How To Use Layer Effects In GIMP {Complete Guide}

If you’re ready, let’s do it!

Pro Tip:

Make sure you have the latest version of GIMP installed. If not, that’s o.k., since all questions are relevant to older versions too. The main difference might be how the interface, panels, and icons look in my version (2.10.22) vs. yours.

Also, here’s how to update GIMP for Mac or to update for PC.

How To Create Layers In GIMP

Once you open an image or create a new canvas, you’ll have your first layer. But what if you need more layers?

To add a new layer, navigate to the bottom of the Layer Panel, and click the first icon. After clicking it, a New Layer dialog window will appear.

From here, you can add attributes to the layer, like;

Another handy feature is changing the layer’s dimensions if you’d like it to be different vs. the canvas. This is helpful when adding a new image that’s a different size from the one you opened. Adjust the width and or height to match the document you’re working on.

Once you’ve selected the layer attributes, click ok, and your new layer will be added to the Layer Panel.

Pro Tip:

Use the keyboard shortcut of; Command (Mac) or Ctrl (PC) + Shift + N to create a new layer.

Use Color tags to represent different edits; Orange for Hue/Saturation, Blue for White Balance, etc. Or whatever helps you organize the layers.

How To Fill a Layer With a Solid Color Or Pattern

A vital element of creating a new layer is deciding on what to fill the layer with. It can be set to transparency, a solid color, or a pattern.

The Foreground and Background will set to your color swatch (under the tool icons in the toolbox). White will add, well, a solid white color.

Transparency will make the layer void of any pixels. This is ideal for graphic design projects where you need a portion of the layer to be transparent. For example, when creating logos or other types of designs.

How To Fill With a Pattern

Choosing “Pattern” will fill the layer with the pattern selected. Selecting a pattern via the New Layer window isn’t possible, though.

Instead, before you create a new layer, select your Bucket Tool. Then, to set the pattern, go to the Tool Options, click on “Pattern fill,” and choose your pattern. Now, when you select “Pattern” while creating a new layer, it will auto-fill with that pattern.

How To Rename Layers In GIMP

I like to rename layers to help remind me what that layer is all about. For instance, if I use the Curve Tool, I’ll rename it to Curves Edit.

We’ve already covered how to name a layer when creating a new one. But how do you rename an existing layer? Here’s how…

How To Use Layer Masks In GIMP

Add a Layer Mask for advanced edits.

So many options. Which one do you choose? Either White or Black for now, and then check out my Layer Mask guide for an in-depth look at these.

A Layer Mask is an advanced type of layer. After adding a Layer Mask, you can adjust parts of the layer’s Opacity. This is especially helpful when you need to pinpoint an edit for only a portion of the image.

For example, let’s say you want to increase the Saturation of an image. However, the increase in Saturation makes skin tones look unnatural. By using a Layer Mask, you can remove the Saturation boost from the skin!

To add a Layer Mask, click on the second to last icon at the bottom of the Layer Panel (it looks like a clown). The “Add Layer Mask” dialog window will pop up with some choices.

The most common choice of the bunch is White or Black. White sets the Mask to full Opacity, and Black sets it to full transparency.

When using Layer Masks, keep this in mind;

So, if you add a Black Mask, the edit on the layer will be set to invisible. If set to White, the entire edit is visible. Here is the power of Layer Masks…

…to pinpoint your edit to a portion of the layer you’ll paint with Black or White!

Using our Saturation edit example from above, we can remove the skin’s edit by adding a White Layer Mask and painting over the skin with a Black brush.

At the beginning of this article, I mentioned several guides on layers. Check out the one on Layer Masks for more tips for using them.

How To Select a Layer In GIMP

The “Original Image” layer is the active layer.

You’ll know which layer is active when you see a layer that is highlighted. To select a different layer, click on it to make it active.

How to Select Multiple Layers

I’m disappointed by this news too.

One of the most asked questions I get from students is how to select multiple layers. I find this comes from those that are transitioning from Adobe Photoshop.

Unfortunately, it’s not possible to select multiple layers at this time. However, there is hope for the possibility of this in a future release of GIMP. It’s actually scheduled for GIMP 3+ per the developer’s road map.
A temporary fix is to place multiple layers in a Grouped Layer. Check out number Twenty to learn how.

Change Order of Layers

Get organized by rearranging the order of your layers.

After editing in GIMP for a while, you’ll realize you’ll need a lot of layers to achieve your creative vision. You’ll also notice that if a layer is out of order, it can have detrimental effects on your final edit.

To change the order of layers, you have two options;

Show or Hide Layers

Only the Image layer is visible as I’ve turned off the others.

At times, you may wish to hide a layer while working on others. Then, when the time is right, you can reshow the layer. You can show or hide a layer by enabling it or disabling it.

By default, a new layer is enabled, and it’s denoted by an icon that looks like an eye. This icon is located to the left of the layer. Click on it to hide the layer and click in that area again to reshow the layer.

How To Merge Layers In GIMP

2 layers have been merged with the third in the group.

You have two choices when it comes to merging layers. Either merge the active layer with the one below it or merge all visible layers. The first option can be accomplished one of two ways;

Merging all visible layers is helpful when you need to merge 2 or more layers at once. If you have other layers that shouldn’t be merged, make sure to hide them before merging.

To merge all visible layers, right-click on any visible layer and select “Merge Visible Layers.”

How To Delete a Layer In GIMP

There’s a chance you will create a layer you’ll no longer need. You can hide it or delete it. To delete it, click on the delete icon at the Layer Panel’s bottom (last icon).

How To Delete Only the Pixels Of a Layer

It’s possible to delete the contents (pixels) of a layer and keep the layer active, with transparency. This will save you the step of having to create a new layer after deleting it. Here’s how…

Go to your menu under Edit and click Clear.

How To Add An Image To A Current Project

Some projects will require multiple images. If you open all of them, they will do so in separate tabs. There are three ways to add an image to an existing canvas.

The first method is to go to File and choose “Open as Layers.” Locate your file to import and click OK. The image will be added as a new layer.

The second way to add an image as a new layer is to open one or more files as usual.

Go to the tab of the image that needs to be added. Then, click on the image layer and drag it over the document’s tab to be added to. Once you release the mouse button, it’s included as a new layer.

The final way to add additional images is to open your operating system file folder, locate the file, and click/drag it over the GIMP interface. Once you release it, it’s added as a new layer.

How To Overcome "Bugs" When Working With Layers

The last tip offered three methods for adding an image to another document. Methods 1 & 2 do not always work, especially for those using Windows 10.

If this happens to you, I encourage you to report the bug here. Hopefully, with enough reports, the developers will fix this sooner rather than later.

How To Lock a Layer In GIMP

Mistakes happen. Sometimes you’ll find yourself working on an edit only to realize you’re working on the wrong layer! To prevent this, I recommend locking layers from being accidentally altered.

To lock a layer, click on the layer to be locked to select it. Then, click on the brush icon to the right of “Lock:” (under Opacity in the Layer Panel).

Add Alpha Channel - What is An Alpha Channel In GIMP?

The image layer does not have an Alpha Channel by default. The reddish area is where I tried to erase part of it and was left with a solid color instead. The color you get is based on the Background color swatch at the time of the edit.

An Alpha Channel is required to add transparency to a layer. This is vital when working on an image that doesn’t automatically have this transparency. For example, when you try to erase part of it.

Instead of being left with transparency, you’ll end up with a solid color. To add transparency to a layer, right-click on it and select “Add Alpha Channel.”

After adding the Alpha Channel to the Image layer, I’m left with transparency. Which you can see based on the area that has been erased. To remove the Alpha Channel (if needed), right-click on the layer and choose “Remove Alpha Channel.”

How To Resize a Layer In GIMP

Grabbing the Scale Tool from the toolbar requires clicking on the canvas to activate it.

The dialog window is detached when choosing the Scale Tool from the menu.

Resizing an existing canvas can be done by going to Image > Canvas Size. Using it will resize all your layers, though. So, what do you do if you only want to resize one layer? Use the Scale Tool, of course!

You can either select the Scale Tool from the toolbar or right-click on a layer and choose “Scale Layer.” Inside the dialog window, set your width, and the height will auto-update to keep the layer’s aspect ratio (in proportion) intact. That is if the chain link icon (to the right) is activated.

How To Crop a Layer In GIMP

Cropping individual layers can be done with the Crop Tool. The key is choosing the right option in its tool options. First, select the layer to be cropped.

Then, grab the Crop Tool from the toolbar or with the keyboard shortcut; Shift + C. With the Crop Tool, click and drag around the area you’d like to keep. Anything outside of the box will be deleted.

Now, navigate to the tool options and make sure “Current layer only” is selected. When you’re ready to crop, hit the Enter key.

How To Copy a Layer In GIMP

When editing, I recommend making a copy of the original layer to prevent it from being destroyed. Doing this will keep the original layer intact since you’re applying edits on the duplicate. This is known as editing non-destructively.

To copy a layer, click on the Duplicate icon at the bottom of the Layer Panel (the fifth icon). Or right-click on the layer and choose “Duplicate Layer.”

Link Layers

2 layers have been linked and are denoted by the chain link icon.

Often, you’ll find yourself needing to move, rotate, flip, and resize a layer. These tasks are easy in GIMP. But, what if you want to do all of the above at the same time? With GIMP, it can be done!

The ability to manipulate multiple layers at once is possible when you link each of them. To link layers, click to the right of the eye icon of each layer to add a link.

Once you have multiple layers linked, you can reposition all of them at the same time on your canvas. Or you could rotate, flip, and resize simultaneously!

How To Group Layers

Organizing your layers is essential for a fast and productive workflow. And for your sanity! The more layers you create, the more critical it will be to organize them.

Grouping similar layers or specific editing steps together makes it easy to find what you need later on. Throughout this tutorial, the images I’ve shown includes a Grouped Layer.

The top layer (Retouched) is the name I gave for the group. Inside, I have three layers that are part of the Grouped Layer.

To create a Grouped Layer, click on the folder icon at the bottom of the Layer Panel. To add layers to it, click and drag a layer over the top of the group layer.

Once you release your mouse button, the layer will sit inside and will be indented to the right. This is your cue that the layer has been set correctly in the group.

How To Make a Clipping Mask In GIMP

Before clipping the layer, I resized the Image layer smaller to fit more of the shape’s subject.

A Clipping Mask allows you to “clip” one layer to another. This is helpful when you want to place an image layer inside of a shape, for example. Unlike Photoshop, GIMP does not have a built-in Clipping Mask.

Instead, here is the workaround…

Add a Layer Mask to the image filled with black.
Add a new layer below your image layer and create a shape.
Use the Fuzzy Select Tool to select the shape.
Click on the Layer Mask to activate it.
Set your Foreground color swatch to Black and the Background color swatch to white.
Hit your delete key. Boom, the image has been clipped to the shape!

How To Center Something In GIMP

Centering something in GIMP depends on what you want to center. Do you want to center text within a line or a layer itself? If you need to align a layer in the center, see the next item.

To align text to the center of a line, use the justify option in the Tool Options before typing your words.

How To Align Layers In GIMP

GIMP has a built-in Alignment Tool that will allow you to align a layer precisely within your canvas based on your needs. Here’s how…

Check out my Alignment Tool complete guide for advanced alignments.

How To Change the Opacity of a Layer In GIMP

I dropped the Opacity of the Grouped Layer to 37.9. She now looks like a ghost!

When editing, you make decisions on the intensity of the tool being applied. However, if you leave the project and come back to it another day, you may decide it’s too intense. For example, you set the Saturation at +50. Too much in most instances.

You can either delete the layer it was applied to and start over or lower the layer’s Opacity to tone it down.

Use the Opacity slider in the Layer Panel to adjust the transparency of a layer as needed.

How To Move Layers In GIMP

Moving a layer within the canvas is sometimes needed to change the composition of it. Or for other reasons. This can be achieved with the Move Tool.

Grab it from the toolbar or use “M.” Now, click on your canvas to move the layer. If you have more than one layer and it’s moving the wrong one, make sure it’s selected via the Layer Panel. Then, in the Tool Options, select “Move the active layer.”

What Is that Yellow Dashed Line On Your Layer In GIMP?

The yellow dashed line is known as the Layer Boundary in GIMP. The Layer Boundary contains the content (pixels) of the Layer within it.

It will affect your ability to add Layer Effects and/or aligning two or more of them. It can also be annoying when visible. I’ll explain how to turn it off in Twenty Seven.

Suppose you wish to add pixels beyond the Layer Boundary. In that case, you'll need to change the boundary size to match the overall document. And or make the canvas larger.

Go to; Layer> Layer to Image Size
If you wish to align two or more layers to each other, then you'll need to decrease the size of the boundary by shrinking it to the actual pixels of the Layer.

Go to; Layer> Crop to Content