So recently for a class project, I found myself needing a slight bump texture. I'm talking about the texture some electronics have for grip. It has tiny little bumps used for grip and kinda look like gravel. Unfortunately, I couldn't find a tutorial or texture that I could use. I figured out a way to make one using Photoshop using a vague little filter called the "Custom" filter.
Here is the outcome.
Fairly convincing. It's all in the fine details. Now here's how it goes.
Start with a medium sized, preferably square canvas in Photoshop. I picked 1024.
Fill the canvas black (Shift+F5, pick Black). The add Noise, Filter > Noise. Change it to Gaussian, Monochromatic. Noise is just noise, so it doesn't really look like anything.
Now go to Filter > Other > Custom. You get this window.
The way this filter works is it uses the numbers in the boxes to offset portions of layer. With the right adjustments, certain spots can appear slightly round and others can fade off.
I got this done before and here are the values that worked for the texture I wanted.
And this is the resulting pattern. Feels rough.
Looks great, but it all looks the same. I like to break up sameness with some Difference Clouds. Filter > Render > Difference Clouds. "Oh, but it looks all cloudy". Go to Edit > Fade. Put it on Darker and mess with the Opacity. It blends the filter with the previous state and as a result, some spots get darker while other stay light. It's up to you if you really need this.
After that, the process is finished. That concludes this short tutorial. You now have a bumpy texture.