Creating an obj file in ZBrush is a simple process that allows you to export your 3D models for use in other programs or for 3D printing. Here's how to do it:

1. Open your 3D model in ZBrush.

2. Navigate to the 'Tool' palette and select the subtool you want to export as an obj file.

3. Once selected, go to the 'Export' button and choose 'OBJ' as the file format.

4. Choose the destination folder and file name for your obj file and click 'Save'.

5. Your obj file is now ready for use in other programs or for 3D printing.

By following these simple steps, you can easily create an obj file for your 3D models in ZBrush. Whether you're a beginner or an experienced 3D artist, ZBrush makes it simple to export your creations for use in a variety of applications.