SubTools provide an excellent way to break your model down into its various components and keep everything organized. Each SubTool’s visibility can be turned on and off, letting you see just the parts that are necessary for what you’re doing at the time. However, you will also often encounter situations when you have some SubTools visible, some hidden and now want to focus on a single one of the visible parts. When that happens, it can be a break in your workflow to temporarily hide several SubTools, do what you need, then unhide those same SubTools again
The Solo feature resolves this challenge beautifully. Quite simply, it instantly hides all other SubTools, regardless of their status in the SubTool palette. You can select any SubTool, press Solo to hide everything else and go right to work. When you want to see the rest of the model again, turn Solo off. Everything that had been visible before turning Solo on will be visible once again, while everything that had previously been hidden will remain hidden.
This is just one of the many ways in which ZBrush continues to search for innovative ways to make the artist’s life easier.