So you've just finished creating an amazing design in Adobe Illustrator and now you want to turn it into a 3D model. But how do you save your Illustrator file as an OBJ? Here's a step-by-step guide to help you out:

1. Open your Illustrator file and make sure your design is ready for 3D modeling. This may include using the 3D tools in Illustrator or setting up your layers properly.

2. Once you're satisfied with your design, go to 'File' and select 'Export'.

3. In the export window, choose 'Wavefront (OBJ)' as the format. This will allow you to save your file as an OBJ, which is compatible with many 3D modeling software.

4. Select a location on your computer to save the OBJ file and click 'Export'.

5. You may be prompted with export options such as preserving appearance or exporting as a single layer. Choose the appropriate options based on your design and preferences.

And that's it! You've successfully saved your Illustrator file as an OBJ for 3D modeling. Now you can import it into your 3D software and start creating a 3D model based on your design.

It's important to note that while OBJ files can include 3D geometry and texture information, they may not preserve all the Illustrator-specific features such as strokes and effects. Therefore, it's recommended to use simple, flat designs or prepare your artwork accordingly before exporting to OBJ.

With these steps, you can easily take your 2D designs from Illustrator and turn them into 3D models for animations, prototyping, or visualization. Remember to experiment with different designs and explore the possibilities of 3D modeling with your Illustrator creations. Happy designing!