
The real world is dirty. Really dirty. Look closely enough at almost any surface that surrounds us, and you will find some degree of dirt or grime, or decay, or weathering. It's all a part of the natural chaos of this world.
So to create believable, realistic impressions in digital art, some form of that dirty, chaotic mess needs to be incorporated. The problem is that it's rather difficult to create convincingly random and dirty textures using digital tools that are based on mathematical equations. Instead, it's much easier to create it with practical elements and then digitize them for use in Adobe Photoshop.
In this Quick Tip, I'll show you my process for creating convincing grungy brushes with a technique that is easy to do, and doesn't make a huge mess to clean up! The results are also very easy to digitize and use.
1. Create the Practical Effect
Step 1
The materials I used are not hard to find, but might require a quick trip to the craft store:
- some sturdy card stock that won't wrinkle if it gets a little wet
- a bowl with some used coffee grounds (I recommend drinking the coffee first. Yum!)
- water soluble black printing ink
- a thick brush
- a few natural sponges

Step 2
First prepare the ink elements. Add a little water to the coffee grounds, mix with the brush, and then set aside. Squeeze some of the ink out onto a small plate or palette board.

Step 3
Dip one of the sponges into the ink. I chose to use natural sea sponges because their texture is very random, and clearly not manufactured. The printing ink is also ideal because it's too thick for the sponge to absorb, and it makes a very dark mark that is easy to scan or photograph.

Step 4
Dab the inked sponge onto the card stock. Use quick dabbing motions, not brushing strokes, to create the appearance of a very dirty, grime-covered texture.

Step 5
Use the brush to add some of the coffee water and grounds onto the texture. Be careful not to water-log the paper—just add enough to loosen the printing ink.

Step 6
Use a clean sponge to soak up the extra wetness. The amount of coffee used should vary from print to print to create a wide array of different grunge effects.

Step 7
Experiment with different techniques to get good range of effects. One of my favorites was to dip the inked sponge lightly into the coffee water before printing with it.

2. Going Digital
Now that we've gotten our hands dirty and created a controlled mess on paper, it's time to turn those dirty spots into pixels!
Step 1
Be sure to wait until the paper is completely dry first. If the textures involve loose coffee grounds, I recommend photographing them instead of scanning. Just be sure the camera is looking straight down on the texture and the lighting is nice and even.

Step 2
Open the photo in Photoshop. Go to Layer > New Adjustment Layer > Curves Use the white eyedropper from the Curves properties panel and click on the paper background to force it to be the white point.

Step 3
Adjust the Curves points to meet the outside edges of the histogram and increase the overall contrast of the texture.

Step 4
Photoshop disregards color information when creating brushes, so it's useful to view the texture like that first, just to make sure the color loss doesn't produce unexpected results. Go to Layer > New Adjustment Layer > Black & White.

Step 5
When using a custom brush in Photoshop, there's nothing worse than seeing one with a hard edge. That is caused by the texture exceeding the bounds of the canvas.
As a precaution, add a New Layer over the photo and use a soft round brush to paint a white border completely around the edges. Take this opportunity to also paint over any distracting spots or elements.

Step 6
Click on either the photo layer or the white background layer to make them active, and go to Edit > Define Brush Preset. Photoshop asks for a brush name, and then when you press OK, this new brush is added to your list of Brush Presets.

3. Use My Brushes
I fully encourage you to create practical effect brushes on your own. It's not a very difficult task and it is incredibly rewarding. Cultivating the skill to transition visual effect from practical to digital will open up new possibilities for your digital designs. But if you don't have the time or capability to create these brushes on your own, I've included mine here for you to use.
Download the attached file for this tutorial, DirtGrimeBrushes.abr
. Then go to Edit > Presets > Preset Manager. In the Brushes section, use the Load button to navigate to the downloaded file.

This will add 13 new Dirt brushes to your list of Brush Presets.

Want More?
Can't get enough custom creative
brushes in Photoshop? Check out the other posts in this series for creating Photoshop Brushes From Scratch. Hungry to learn more about how to use custom
brushes in photo manipulation projects? Check out my profile of courses and tutorials here at Tuts+ and find all that, and much more!
Creating your own library of digital resources pulled from real-world practical effects is a skill that will pay off exponentially in the future. Instead of searching stock sites for interesting textures, try creating some for yourself! I'd love to see them in the comments below.