Join Justin Seeley for an in-depth discussion in this video What are layers?, part of GIMP Essential Training (2012).
One of the most essential functions of any image editing application that's really worth its salt is going to be the use of layers, and GIMP is no exception to that rule. Layers are a big part of anybody's workflow inside of GIMP, and if you've never used an image editing application before, you might be wondering exactly what layers are. So in this movie, I'm going to give you a little bit of insight edge to what layers are, and kind of simplify what they mean in terms of how they work inside of GIMP. So, what exactly is a layer? Well, if you think of an image, when you first take a photo, or something like that, inherently it is flat, right? There is no depth to it whatsoever. It's just one single photo, or one single image that you bring into an image editing application like GIMP.
So most of the time, you'll see something that looks like this; just one single image on something like a background layer. What I want you to do is think of layers in terms of a window, and so the Layers panel, in essence, is a window into the document in which you are creating. And each time you add another layer, or another image on top of the image that you're working on, you're setting up another layer of depth to that scene in which you're looking through the window.
So right now, I'm looking at the background. So think of this window that we're looking at right here as the furthest point away from me at any given time. This is how far I have to go back until I reach the end of the photo. If I turn on this layer here, Window 1, that steps one layer closer to me; one layer closer to the foreground, because as I go up in the Layers panel, I'm coming closer to me in the photo. And let's turn on Window 2 here, and so there's another layer right on top of that, and then finally I'll turn on the text.
So the text is the foremost object that we see, it says Layers, and then as we step back through the windows, you can see the different layers that we have. So behind Window 2 is Window 1, and behind the Window 1 is the background. Now I've disabled these two layers in the middle, leaving only this layer on top, so I should see the text, and the original background, right? Just like that. So when you are talking in terms of a layered composition, basically what you're talking about is just several sheets of paper, or several photographs layered on top of one another that can be manipulated individually, changed individually, and altered in any way you see fit here inside of the canvas.
The canvas is locked into the rectangular form factor that you see here, and it cannot be changed. Although the size might differ from document to document, it will always be landlocked into this rectangular or square setting that you see here. Layers, however, have a little bit more freedom in that the layers themselves, like this text layer, for instance, can take on the form of letters. They can be transformed, rotated, skewed, scaled; whatever you want to do to them, they can have done to them here inside of this document. There are no constraints on the layers themselves; only a constraint on the canvas that surrounds it.
So as you continue to build new things in GIMP, whether it's an advertisement, a Web site mockup, just working on a photo, whatever that might be, adding layers to your document is a great way to ensure that you get the most out of that document, and it's also a great way to ensure that you're being what we call nondestructive to that document as well, because as you work in layers, you can always take away, redo, undo, move, change, scale; do whatever you need to do to those layers in order to make them work with the layers underneath them.
You also have the ability to blend these layers together as well. Now, if I wanted to, let's say, move the layer's text here, that's very simple. I just select the Move Tool, and I'll just grab that layer, and I can just move it anywhere I want. You notice it moves independent of the rest of the objects in the scene. Let's turn on the other two windows, like so, and I'll grab Window 2 here, and I'm just going to move it over to the left. And so you can see Window 2 moves over. There is Window 1 directly underneath that. Let's click on Window 1, and let's move it a little bit to the right.
So you can still see a little bit of it, and then the background is actually shining through both of those. So there you can see, I've moved all of these objects independently of one another, which is pretty neat. Now, I can also, let's say, take this tool, the Rotate Tool, and I can just give this a little bit of rotation. And we'll cover how to rotate in a later movie, but I just want to show you. So here we go; I'll rotate that. So as you can see, the background layer has now been rotated. You can see specs of transparency. That's, again, because the canvas area is landlocked to this rectangular form factor, but the layers themselves are able to be independently manipulated and controlled, because they live on separate planes from the actual document itself.
So as you look in the Layers panel here, there is actually an invisible layer that actually doesn't show up in here. That's the canvas, the background; the firm background layer of this document. That's the square form factor that cannot be changed. Anything on top of that, from the bottom to the top, goes backward to forward all the way until what's fully in the foreground, which is at the top of the Layers panel. So as you work in this program, or in any program that has layers, that's basically what you're dealing with. You're dealing with a stack of objects that can be manipulated, scaled, rotated independently of each other, changed independently of each other, relative to the document. It's a great way to work, and I really encourage you to do so.
So as we continue to explore layers inside of this chapter, I encourage you to play around with them, see what all they can do, and then put them to play in your personal workflow.
- What is GIMP?
- Performing nondestructive edits with layers
- Exploring blend modes
- Adjusting transparency
- Making selections
- Creating layer masks
- Adjusting color and contrast with Curves, Levels, and other auto adjustments
- Sharpening images
- Using patterns and gradients in your images
- Fixing image flaws
- Enhancing photos with filters
- Automating your workflow
Skill Level Beginner
Q: This course was updated on 09/04/2014. What changed?
A: We added a movie that explains why you can't achieve some of the effects shown in these tutorials in the Windows version of GIMP. This is due to the fact some plugins have been removed since this course was recorded. Watch the "IMPORTANT: Before we get started" to learn more about how these changes will impact you.
Q: I don't have access to some of the tools and can't create some of effects shown in this course. What's wrong?
A: Unfortunately, some plugins have been removed from the Windows version of GIMP since this course was recorded. Watch the "IMPORTANT: Before we get started" to learn more about how these changes will impact you.