This question has come in through various channels in recent years, so I thought I'd do a write up on a quick fix. If you've ever wondered why your brushes look “pixelated,” there's a perfectly good explanation. Photoshop isn't broken, you aren't missing a setting, and you probably got here because you like keyboard shortcuts. This tutorial lesson is important for beginners who are struggling with keyboard shortcuts. Photoshop features are a lot more complex than you think therefore you have to keep a keen eye on advanced settings and customizations.
You probably think you're crazy because you hit “B,” the keyboard shortcut for the Brush tool, and all your brushes still look like crap. This is probably because you are not actually selecting the brush tool. The keyboard shortcut for the Pencil tool is also, you guessed it, “B.” When the pencil tool is selected, all the brushes will appear pixelated. Take a look at your tools and make sure you actually have the Brush tool selected. Hold down on the Pencil tool to select the Brush tool.
That's it! You were just a victim of your own productivity (Evil Twin Keyboard Shortcuts). You can always change the keyboard shortcut for the Pencil tool to prevent future attacks 🙂
The same technique can be applied to other keyboard shortcuts if you are struggling and not moving to any direction. Make sure that you are using the right tools for your project and do not get tangled with the similarity between different tools.
This particular issue has been discussed widely across all the discussion forums so keep your mind clear and do not use keyboard shortcuts if you are struggling to use them properly. Before making use of keyboard shortcuts, consider checking which keyboard shortcut has been assigned for which particular task. To check the default keyboard shortcuts for your photoshop application, toggle to edit and keyboard shortcuts for customizing those shortcuts.