In this help article I’ll be showing you how to create a transparent gradient using GIMP. This is a very easy, beginner-friendly technique that allows you to have your image slowly “fade out” to transparency, or basically gradually erase the image. You can follow along using the free image I downloaded from Unsplash here. You can watch the video version of the tutorial below, or scroll past it for the full help article. Let’s get started!
Step 1: Open Image Into GIMP
To start, you’ll want to import your image into GIMP if you haven’t already. You can do this by going to File>Open, and selecting the file location on your computer. You can also simply drag and drop your image into the main image area of GIMP (follow the red arrows along the green dotted line in the image above).
Once your image is in GIMP, you may get asked if you want to convert the image to GIMP’s native sRGB color space. I recommend hitting “Convert” (red arrow in the above photo) unless you need to keep the image’s original color space for a specific reason.
Step 2: Add an Alpha Channel
With the image imported into GIMP, you’ll now want to complete the important step of adding an alpha channel to your image layer. To do this, right click on the image layer over in the “Layers” panel (red arrow) and click “Add Alpha Channel” (green arrow). This step is important because without an alpha channel added to your image, your image will erase to a color rather than to transparency.
Step 3: Add a Layer Mask to Your Image
With your alpha channel added, next what you’ll want to do is add a layer mask to your image. This will allow you to non-destructively add a “transparent” gradient to your image. To add the layer mask, click the layer mask icon at the bottom of the Layers panel (red arrow in the image above). You can also right-click on the image layer and select “Add Layer Mask.”
In the Layer Mask dialogue that appears, under “Initialize Layer Mask To:” select “White (Full Opacity)” (green arrow in the above image). Click the “Add” button at the bottom of the dialogue (blue arrow).
You should now see a white box directly to the right of your image thumbnail in the Layers panel (red arrow in the above image). This white box is your layer mask.
Step 4: Draw a Gradient On Your Layer Mask
Next, grab the Gradient tool from your toolbox by clicking and holding your mouse on the tool group that contains the Bucket Fill Tool (red arrow in the image above), then releasing your mouse on the “Gradient” tool (blue arrow). You can also simply hit the “G” key on your keyboard to access this tool via the shortcut key.
With the gradient tool selected, click the tiny icon below your foreground and background swatch colors (towards the bottom of the Toolbox – red arrow in the image) to reset your colors to black and white.
Now, come over to the “Tool Options” section for the Gradient tool (usually located directly below your Toolbox – if not visible go to Windows>Dockable Dialogs>Tool Options). Click the “Gradient” button (red arrow in the above image) and select one of the gradients that changes from black to white (outlined in blue) – I went with the “FG to BG (RGB)” option by simply clicking on it.
Click the “Shape” dropdown (red arrow) and select “Linear” (blue arrow).
Finally, click and drag your mouse on your composition to draw the gradient (tip: hold the ctrl key on your keyboard to draw in straight line mode). Your image should now appear as though it is fading out, or erasing, to transparency using the gradient.
Note: you can always reverse the direction of the gradient using the “Reverse” button in the Tool Options (green arrow in the above image). Then you can click and drag the gradient endpoints to reposition them on your image.
One end of the gradient will contain white, which will contain opacity or display the pixels in your image, and the other end of your gradient will contain black, or contain transparency that hides your image. In this example, the left point of my gradient contains white (red arrow in the image above), and the right point of the gradient contains black (blue arrow in the image).
I can click and drag either endpoint with my mouse to adjust at what point the fading out begins, and at what point the image is totally faded out and now transparent.
If you hover your mouse over the line between the two endpoints, you’ll see a small circle appear towards the middle of the line (red arrow). This is the “midpoint” of your gradient.
You can click and drag the midpoint to adjust the point at which the image is at 50% opacity, which changes the rate at which the image fades to total transparency. For example, if I drag the midpoint to the left, my image will start to fade out to total transparency sooner.
When you’re ready to apply the gradient, hit the enter key on your keyboard. If the gradient doesn’t apply when you hit the enter key, just grab another tool from the Toolbox like the “Move” tool.
If you look at your layer’s image thumbnail in the Layers panel (red arrow in the above photo), you’ll now see the white box has a gradient that gradually changes from white to black (or black to white, depending on what direction your gradient is going). Your image now gradual fades to transparency using a gradient!
Step 5: Export the Image with Transparency
If you want to export the image WITH the gradient transparency intact, you can do so by simply going to File>Export As (red arrow), then export the image as a filetype that supports transparency (some examples include PNG, WebP, GIF, and TIFF).
So, if I want to export my image as a PNG, I can rename my file and make sure it ends with “.png” (red arrow) – the PNG file extension. Click “Export” to export the image (green arrow).
You can stick with the default values for PNG and click “Export” again (red arrow), and now your image will be exported with the transparent gradient.