Pixelmator Pro is a layer-based image editor. This means that instead of simply editing one image at a time, you can add and combine multiple layers of different kinds — images, shapes, and text — to create your compositions and designs.
You can think of layers as stacked transparent plastic sheets. If you add a completely empty layer (an empty sheet) and draw on it, the parts you draw over will no longer be transparent, but the parts you don’t touch will stay transparent. You can also add images or photos as new layers — if an image is smaller than the canvas, around the image, you’ll be able to see the layers below (if there are any).
You use layers for a wide variety of different tasks in image editing, but a few of the more popular ones are adding text and shapes, copying parts of one image to another, and creating posters or collages.
A new image in Pixelmator Pro contains one layer — either the image you opened, or an empty white layer if you created an empty image. To create new layers, you can add photos or other pictures as layers, create layers from selections, and add shapes or text. Pixelmator Pro can even add a layer to your composition directly from your FaceTime camera.
To work with layers, you should have the Layers sidebar visible. Using the Layers sidebar in Pixelmator Pro, you can select layers, create new layers, remove layers, show and hide layers, arrange layers in the layer stack, group layers, add layer masks, and more.
Tip: The layer you are working on is highlighted so you can easily identify it. It’s a good idea always to check which layer is active — for example, if you choose a command and nothing happens, check whether you’re editing the right layer.