I made this wallpaper recently. I really like how this turned out and it was pretty easy to make, so I figured I give a step by step guide to anyone who’s interested in replicating it; I expect that most people will play with and expand on my original idea.

Note: All of the images are big, just click on them and they’ll get big enough to see what’s going on.

So, let’s take a little walk through GIMP and see how using layer modes and layer groups can give us really cool effects. To start, open GIMP and create a new project (>file>new). I have a monitor with a 1920×1080 resolution, so I always try and make my wallpapers 16:9 and 1920×1080 at the smallest. For this project I set the width to 1920 and height to 1080 pixels. I’m going to provide all the source images I used below, so you don’t have to search all over the internet for them. I would note though, I constantly look for unique, cool wallpapers I can use as ‘source’ images in my projects.

redspace

bluespace

color

psychedeliccolor

waves

crowd

After downloading those pictures, go ahead and drag them into gimp. The first thing you’ll probably notice, is that some of these images aren’t big enough to fill the entire image. We’ll fix that in a minute. First, after saving, always remember to save, clicking crtl+s is just habitual for me now, we need to add an alpha channel to each of our layers. Right click on each layer and click on the option to ‘add alpha channel.’ Adding an alpha channel adds transparency in each layer. Next, turn off every layer but the one I titled redspace.

You’ll notice that we need to make this layer bigger. To do that click shift+t or select the scale tool in the toolbox. Scaling an image, especially as much as we need to for this, is usually not a great idea, because you lose a lot of quality as you scale an image up. Luckily, we’re not relying on the details of this image, just the general feel of it; though, admittedly, it would be better to use a larger image. I scaled the image, redspace, to 2045×1151. After scaling the layer I moved it. Do this either by selecting the move tool in the toolbox or by clicking m. I moved the layer into place, leaving the watermark out of my image. The next layer that I scaled was the layer I’m calling ‘color.’ While scaling this layer I clicked to lock the chain in the scale tool options, this means that each side of the layer will scale in proportion. I scaled, as you can see, this layer to 1920×1200. I then moved the ‘color’ layer into place, filling the entire image. There are two more layers to scale, but I figure you can probably get those yourself once I give you the numbers. For the ‘crowd’ layer is used 1995×1337. I also desaturated the crowd layer, to do that go to >colors>desaturate>luminosity. For the waves layer is used 1532×862. OK, hopefully you have something that looks like this.

The next step required me to play around and try a few different things, but I’ll just give you clear instructions to achieve the effect I showed at the top. In reality, I didn’t have any specific goal when I started and I just messed around with different images until I got something cool. I’m not going to force you to read about me playing around with GIMP for hours, instead I’ll give you the next step. Create a layer group. Then create another. I named them color and space respectively. You can change layer and layer group names by double-clicking on the layer or layer group name. Drag the space layers, redspace and bluespace, into the space layer group. Drag the color layers into the color layer group. This should leave you with two layer groups that have two layers each and two layers without a group. Like so.

Almost done, I swear, all the hard work is out of the way. We just need to order the layers, chose the right layer mode, and set each layer’s opacity and then we’re done. Because I enjoy things looking like magic we’re going to order the layers first, then we’ll set the layer modes and opacities. This will make the image ‘appear’ out of nothing; which looks cool to me. Rather than writing the steps for ordering the layers I’m just going to post a screen grab of the correct order, but first, be sure to center the waves layer if it isn’t already centered. In case you don’t know, layers can be re-ordered via dragging with your mouse or using the arrows next to the create layer group button, you can duplicate layers or layer groups via the button on the right side of the arrows. Here’s the way to order your layers.

Now, for the magic. Let’s adjust the layers modes and opacity of each layer. I’m going to go from the bottom up, so that when you adjust the final layer the image pops out at you. The bottom layer, you’ll remember, or see, is bluespace. I’m going to walk through setting this layer up properly. After that you’ll understand how to change each of the following layers to the settings I’ll provide. The bottom layer, bluespace is actually left at 100% opactiy and in the ‘normal’ layer mode, uh, yeah, should’ve planned ahead, so actually I’ll walk you through the layer above it, redspace. The ‘redspace’ layer is left at 100% opacity, but the layer mode is changed to addition. To change the layer mode, click the word normal, next to mode, and select addition. I’ll provide an image for this. To change the opacity of a layer click in the blue box labeled opacity and drag the blue to the correct number; I’ll insert an image for this as well.

Here’s the list of layer modes and opacities from bottom up.

layer name – layer mode – opacity

———————————–

bluespace – normal – 100%

redspace – addition – 100%

space – darken only – 100%

crowd – grain merge – 38%

color – difference – 62%

psychedeliccolor – subtract – 100%

color(layer group) – grain merge – 63%

waves – overlay – 64%

bluespace#1 – normal – 100%

redspace#1 – addition – 100%

space copy – multiply – 50%

Here’s how things should look now

And finally, set the layer ‘crowd copy’ to multiply at 100% opacity. See, it looked cool didn’t it? I hope this tutorial has been easy enough to follow and has shown you some of the cool effects you can achieve just by adjusting layer modes and layer opacity. If you couldn’t follow something or just have questions, fee free to ask. I, of course, always recommend playing around in GIMP to learn what everything does. Here’s the finished version in GIMP, to save the picture go to >file>export.

I hope this was useful for someone, or at least interesting. I wrote a guide to installing GIMP in ElementaryOS earlier and hopefully I’ll type a few more tutorials in the near future, so be sure look for those. This is my OC Favorites album on imgur: http://imgur.com/a/3ATJa.