Most of the time when we talk about color in the digital art world, we want to make sure colors are vibrant and accurate. But what happens if you want to do the opposite and fade your image?
There are a few different tricks you can use to get a range of different fade effects, so let’s take a look at some of the most popular methods to fade an image in GIMP.
Fading With Opacity
The most basic method for fading an image is to use the Opacity slider, and it’s very easy to do once you know where to look. It doesn’t produce the most exciting results, but it’s still a useful tool to know.
With your image open in GIMP, locate the Layers panel in the bottom right corner of the interface. If your Layers panel is missing, bring it back with the keyboard shortcut Ctrl + L (use Command + L if you’re using GIMP on a Mac).
If you’ve got more than one layer, select the one you want to fade and adjust the Opacity slider at the top of the Layers panel to your desired setting.
If your image only has one layer, you’ll immediately notice the checkerboard pattern that GIMP uses to indicate transparent pixels.
At this point, you can save your image for use in another program if you’re happy with it. Just be sure to save it as a PNG file, since the more common JPG format doesn’t support transparency.
If you want to set your image against a colored background, create a new layer using the keyboard shortcut Ctrl + Shift + N (use Command + Shift + N on macOS).
Click and drag the thumbnail or use the arrow icons at the bottom of the Layers panel to place the new layer below your faded image, and then use the Bucket Fill tool to fill the layer with the color of your choice.
Fading With Layer Masks
If you want to get a more complex fade effect, you’ll need to have control over the opacity of each pixel individually using a layer mask. That might be complex, but layer masks are one of the most powerful tools in image editing and they are actually fairly simple to use once you know how they work.
A layer mask acts like an invisible secondary layer that sits over the top of your existing pixel layer. If a pixel on the layer mask is white, the corresponding section in the main pixel layer is visible, and if a pixel is black on the mask, the corresponding section is transparent.
Grayscale tones allow you to create sections of partial transparency, and that’s exactly what we need to fade an image gradually.
With your image open in GIMP, right-click on its thumbnail in the Layers panel and choose Add Layer Mask from the popup menu. You can also use the small mask icon at the bottom of the Layers panel, or even use the Layer menu, but they all produce the same result.
For this method, set the Initialize Layer Mask to: option to White (full opacity) and click Add. You’ll see a new thumbnail appear in the Layers panel, showing the layer mask thumbnail which is currently filled with white pixels. If you initialize to Black (full transparency), your image will disappear until you paint some white pixels onto the layer mask.
Now you can use GIMP’s excellent paint tools to fade any parts of your image that you want. Using a large soft brush will give you a gentle fade, while a harder brush will make for harder edges.
You can also apply gradients to your layer mask using the Gradient tool, just the same as you would in a normal pixel layer. Remember to fade between black and white, though, or you might get some unexpected results when GIMP converts your colors into grayscale values supported by layer masks.
Last but not least, I wanted to mention selection feathering. The name might seem a bit silly, but it’s a great way to take your selection skills to the next level. Feathering softens the edges of a selection area so that there is a gradient of effect instead of the usual hard edge.
You can customize the amount of feathering before you draw a selection using the Tool Options panel, and you’ll see the results immediately.
If you’ve already made a selection, you can also feather it by opening the Select menu and choosing Feather.
This is a very quick way of fading out an image by combining feathering with a simple press of the Delete key, but it’s not nearly as flexible as using layer masks, so I don’t recommend using it unless you’re making a simple throwaway image.
A Final Word
Like a lot of things in GIMP, there are many different ways to fade an image, and I can’t cover all of them in this post. If you want to get really advanced, you can even fade an image so that it looks like the old-style sepia type that many people associate with the 1800s, but it takes a lot of work to make it convincing.
If you’ve got a different technique you use to fade images in GIMP that I didn’t cover here, let me know in the comments and I’ll give it a try!About Thomas Boldt