Alrighty. Paperdigits nudged me to stop being so much of a lurker 
, so I’m going to start cross posting my tutorials over here as well. This one goes over how to add overlay textures to your images. For some of you it may be a little basic, but these were written with the intent of being read by brand new users who haven’t used a program like this before.
[Originally published on Patreon here]
Texture overlays are a quick way to add a bit more pizzazz to your creative photography. I like using them with portraits. For this post, I’ll be using GIMP, a Tin Foil Bokeh stock image that I created and a quick snapshot of my roommate from testing a new lens. I already edited it for color and contrast in darktable before opening GIMP to add effects to it.
For the overlay texture, I wanted to pick one that would allow the brightest bokeh to fall to the left side of her face over the leaves. Starting images here:
You’re going to open both of them in GIMP, then copy/paste the texture over your portrait. You’ll likely need to resize your texture layer to fit how/where you like it. I didn’t want any of the bright yellow spots to cover her face, so I resized it and moved it around until I liked the placement.
Then comes the fun part of playing with different blend modes!
Above your layers you’ll see a ‘mode’ drop down menu and an opacity slider. I used Screen to brighten up the photo for this one, but there’s a bunch of stuff and I always flip through it at least once to see the other modes anyway. Eventually you’ll learn approximately what effects each one will have, but I couldn’t tell you the technicalities of it if I tried.
All the blend modes you have to work with:
If you like an effect, but its too strong, just drop the opacity on the texture layer.
100% w/ Screen:
50% w/ Screen:
But we’re not quite done yet! From here you can fine tune your image further. I thought the greys in the original stock image washed out the contrast too much, so I used a curves adjustment (color > curves) on the texture layer to bring some back.
There are also times when you’ll need to create a layer mask and remove sections of texture, which comes with its own set of problems. I picked a texture exactly where I needed it so I didn’t feel I need to mask anything out.
Final result:
And that’s the basic idea of how to apply a texture overlay. Different images will require different blend modes and other adjustments, but the idea is pretty universal. I’ve used the layer blend modes to replicate old photo effects, as well as a base for more advanced composite techniques.
Other examples I’ve done of textures and blend modes being used:
Added a Heads Up Display:
Composite of two different images:
All sorts of textures and stuff added to create a comic/poster effect:
Let me know if you have any questions or need clarification on anything! If you like the idea, I’ll keep posting more like this as I make it!