Leather is one of the most difficult material to reproduce right. The main reason is simple: The average leather texture and particularly the bump textures, you find online is simply bad.
Leather appearance comes 99% from a good bump and a good reflection, the rest is just basic color information, so to create leather I would rather search for or create a good skin bump texture than for a leather texture.
In this tutorial we have used this texture that can be found freely here:
So first things first, a good leather starts with a good bump texture. We found this one on the web, it works ok but it's a bit 'harsh'.
So we edited it in Photoshop to get something smoother and more coherent.
Using a process similar to the one described in the Managing bump maps tutorial, copying layers and using various levels of blur and blending modes.
Next we choose a color, it's up to you and your end goal but in our case we went for a classic brown leather.
The color texture was generated from the bump one using the Photoshop's hard light blending mode on a fill layer and some more blurring.
For a more natural effect, we copy the Color texture into the Edgeting channel and adjust its brightness to 50%.
The Roughness parameter was lowered to 80% as well.
Next we add some reflection by enabling the Coatings. Leather is reflective but the reflection is not very intense so the Color and Edgetint values used here are respectively RGB 50,50,50 and 80,80,80
For more realism, we will use a modified version of the bump map into the Coatings Roughness channel.
Indeed leather is often quite shiny on the surface and rougher inside the skin's cracks.
To reproduce this effect we simply blur the bump map in Photoshop and adjust its levels so it looks like this:
Now let's check this material in a real scene. The tiling was kept relatively low on purpose to show the leather effect better.