Adding Tattoos to People
Learn how to add tattoos to the subjects of your photographs by using the displace filter.
For this tutorial, we are going to add this tattoo:
To this photo:
Let's get started. Open the image of the person you want to tattoo in the GIMP. Then, drag the file that contains your tattoo on top of your canvas to add it to the image as a new layer (or you could draw your tattoo on as a new layer over the image). Now resize, move, and rotate the tattoo to place it over your --victim's-- subject's body. You should have something like this:
Now, a very important step: Select your tattoo layer. Then, click "Layer > Layer to Image Size" to make your tattoo layer the same size as the photo layer.
After you've done that, make sure your tattoo layer is selected then click "Filters > Map > Displace":
Make sure to select the layer that your subject is in for both X and Y displacement. You can experiment with the amount (I've set mine to 5) and see what works best for you. Click OK when you are happy.
Finally, just set your tattoo layer to Multiply and you're done (you may want to try out other layer blend modes and use what suites you)!
Note: This tutorial was inspired by this tutorial. You may want to read that too.