As a GIMP user myself, trust me, I feel you. I know how frustrating it can be, when one is looking for a nice mockup file in order to better showcase their products on their social media profiles and / or their websites: basically ALL files are PSD files with Smart Objects and such, and for those who do not have a license of Photoshop, it can be a real pain.

However, the developers of GIMP did a good job into parsing PSD files in order to kind of “decode” (for the lack of a better word) the Smart Objects feature into something usable. Surely it is necessary to try different files, because of factors like complexity or which version of Photoshop this file was created, but still. With a bit of patience and trial and error, one can create a nice work like the one on the top of this post.

Let me show you how I set up this particular mockup on GIMP – I normally work on an Ubuntu Zesty machine with the Ubuntu Studio Graphics package installed. This how-to should totally work on Windows as well.

I used the Hanging T-Shirt Mockup PSD from PSD Graphics (one of the few websites which is totally OK to whitelist, case you have an ad-blocker installed on your browser, since it has TONS of good resources, many for free). When opening the file for the first time, you will get this screen:

What actually interests us is the layer group “T-Shirt”, which is actually the design of your t-shirt. After hiding the first layer (the one which says “Delete This Layer”), you will get this:

I am pretty sure that all layers are disposed like this because they would be a Smart Object on Photoshop – sadly I cannot check this information, I can only guess it. 🙂 Either way, you can definitely hide the colored layer behind the t-shirt shape as well:

Now the fun will really begin. 🙂

Pick up the desired design for your t-shirt – in my case I will use the Doodle: flowers pattern to reproduce my t-shirt that is actually for sale at my shop on Society6. I will paste the layer at the top of my layers stack (size should be around 2000px of height):

After that, I need to drag this layer below the “Layer 1” which is inside the layer group “T-Shirt”: this particular layer is the wooden hanger that’s holding the t-shirt. (We’re almost there.)

Now, since the layer mode is set to “normal”, this pattern is completely covering the t-shirt. In order to merge it amongst all other layers, I will need to set the layer mode to “multiply” – the opacity can be kept as 100%.

Now it’s just a matter of moving it a bit around, in order to make the mockup more realistic: for instance, I want to keep the pattern below the neckline of my t-shirt.

That’s it!

As I said, it is necessary to have some patience in order to find some compatible mockup files. After some digging, I found these ones, all compatible with GIMP:

Minimalist Poster Mockup

Pillow Mockup (Free Version)

Happy designing!