Rust. That beautifully terrible oxidation of iron elements. It's a fact of life in our world filled with metal and machines. Time and moisture take their toll, and even our most magnificent machines deteriorate. For digital artists who focus on photo manipulations, rust is a reliable way of adding realistic grunge, texture and realism to a piece.
In this Quick Tip we will explore a method of rusting metal without having to wait for nature to do it for us!
1. The Practical Effect
There are several different methods to create rust, but this one is quick, easy and safe. It does still use chemicals, however, so be sure to take safety precautions!
Begin by gathering materials. You will need:
- A sheet of iron-based metal like steel. This can be found at most hardware stores fairly inexpensively. An easy test to see if it is iron-based is to check if a magnet sticks to it!
- A wire brush
- A clean paintbrush
- Hydrogen peroxide
Usually sheets of metal come coated to protect against things like rust. We need to remove that! You can purchase a cleanser to degloss the material, but it's cheaper and easier to just use a harsh wire brush! This also adds a bit of texture to the material and ultimately gives the final effect a more realistic look.
Pour the hydrogen peroxide into a smaller cup and use the paint brush to apply it generously to the metal.
Next pour some salt into the puddle of hydrogen peroxide. Spread the salt around with the brush.
Now just wait! The reaction should start almost immediately. The oxygen of the hydrogen peroxide quickly begins to oxidize the iron elements. You can actually watch the rust bubble and form. It's quite fascinating! The longer you let the solution sit, the more intense the rust effect becomes.
2. Create the Brushes
Be careful cleaning the chemical solution off the material, because much of the colored oxidation will still be in the liquid and it will stain. While the rust will be apparent within the first 10 to 15 minutes, it will take a lot longer if you choose to allow the material to dry completely.
Digitize the texture. Depending on how dry and "crunchy" your rust texture turned out, you may choose to photograph the material instead of scanning it. The challenge with the photography is getting the reflective metal to be evenly lit.
Open the texture image in Photoshop and go to Image > Adjustment > Levels (Control-L). Make sure the outside handles of the Levels control meet the outside edges of the histogram. This ensures the light pixels are fully white and the dark pixels are fully black.
Now switch over to the Channels panel and click through each color channel, making note of which one has the most contrast between the rust effect and the background. For this image, that was the Blue Channel. Then go to Select > Select All (Control-A) followed by Edit > Copy (Control-C).
Click back on the composite RGB color channel and return to the Layers panel. Then go to Edit > Paste (Control-V) to paste the copied blue channel as a new layer.
Grab the Dodge Tool (O) with a large, soft, round brush. Set the Range to Highlights and the Exposure to 10%. Use this to lighten the areas around the edges and remove the uneven lighting of the background.
Switch to the Brush Tool (B) and use a soft round brush with white paint to make sure the edges of the image are fully white. Also paint over any stray or unwanted marks you see in the texture.
The image is ready to turn into a brush now! Go to Edit > Define Brush Preset. Give the new brush a name and click OK to add it to your brush library.
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,
Rust.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 six new Rust brushes to your Brush Presets.
Can't get enough custom creative
brushes in Photoshop? Check out some of the other posts in my 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.