If you’re looking to add some extra oomph to your graphics editing workflow, alpha channels are a great way to go. Alpha channels are simply transparent layers that can be used to control the opacity of specific pixels in an image. To get started, open up Gimp and create a new file. Select the “New” button and select “Alpha Channel.” You’ll now be presented with a dialog box where you can name your alpha channel and choose its color mode. For this tutorial, we’ll be using the “Grayscale” mode. Now that we have our alpha channel created, we need to add it to our image. To do this, first select the layer that contains your image and then click on the “Add Layer Mask” button located in the bottom left corner of the Gimp window. This will open up a new dialog box where you can specify which parts of your image should remain visible while the alpha channel is applied. In our case, we want only the pixels that contain our alpha channel to be visible so we’ll select all of those pixels by clicking on the checkbox next to “All Pixels.” Finally, click on OK to close out of this dialog box and return to your image window. Now that our layer mask is set up, all we need to do is apply our alpha channel by selecting it from the Layers menu and clicking on the “Add Alpha Channel” button located at the bottom right corner of Gimp’s window. This will open up a new dialog box where you can specify which part of your image should be used as your source for creating your alpha channel. In our case, we’re going to use just one pixel from our original image so we’ll click on the small square next to “One Pixel.” Finally, click on OK to close out of this dialog box and return back to your image window. Your final product should look something like this: ..
