I've been releasing some of my Photoshop Brushes, and I've gotten lots of feedback on them, so thank you for that. I've also gotten a lot of questions concerning how to “make” a Photoshop Brush. I labeled my Brushes as High-Res, but that's only because they were really BIG brushes. You can make any size Photoshop brush in exactly the same way. Here's how.
If you want to make a brush that is “High-Res,” you will need Photoshop CS2+. In CS2 and CS3 you can make brushes up to 2500px in size. (height or width) In Previous versions like CS, 1000px is the limit. (and maybe much smaller for really old versions, I'm not sure).
Setup Your File
You all probably know that you can make a PS brush out of just about anything, so setting up your file correctly is key. Wether you are using a scanned image, a photograph, or whatever, you need to set up your Photoshop file in a way that will give you the best results for your brush.
It may be temping to have a file open and see something that you want to make a brush out of and do it on-the-fly within that file, but in order to make a brush knowing it is sized right, it's always a good idea to make a separate file to make your brush.
Setting Up The File:
You may not need a high resolution brush, but what if you need the same brush to be larger 6 months down the road? It's always a good idea to make your brush as large as possible in order to use it for other projects later. If you are in CS2 or 3, You can make your file 2500 X 2500px. If you are running a previous version of Photoshop, you will most likely be limited to 999px, if not less.
You can use a color image to define a brush, but you might find it easier to convert your document to Grayscale in order to get a better idea of what to expect. When defining a brush preset, Photoshop will automatically convert your selection to grayscale to make the brush. White pixels will become transparent (which means you don't have to erase the white/background pixels! Keep reading below for details), Black pixels will be opaque, and everything in between will be see-through black/gray.
Adjust Your Image
It's only natural that your image may need a little tweaking before it's brush-worthy. Here are a few adjustments you can make. (all found in the Image > Adjustments menu)
The Secret About Brush Making
For the longest time I couldn't figure out how people made such detailed brushes, and I kept telling myself that it would take way too much time to clip out the intricate shapes. Well, there's a reason why even the novice Photoshopper can make amazingly detailed brushes. Like I said earlier, since Photoshop defines brushes based on a grayscale, there is no need to erase or clip anything! All you have to do is use the adjustments above (you may want to erase unwanted pixels here ands there) and everything that is 100% white disappears. White=Transparent, so put down that eraser or magic wand, and define your brush.
Define Your Brush
Once you get the right amount of contrast and black/white in your image, you're ready to make a brush. Make sure you have the correct layer selected and do a “select all.” Command/Control + A. Now go to Edit > define Brush Preset.
Name your brush, and you're done!
You should now see your new brush show up in the brushes palette. So? What are you waiting for? Start Brushing!