To properly finish and protect your engraved wood frame, follow these steps:

1. Sand the Surface: Start by sanding the entire frame with fine-grit sandpaper (220 grit) to smooth out any rough edges and to prepare the surface for finishing. Ensure that you sand in the direction of the grain.
2. Clean the Dust: After sanding, use a damp cloth or tack cloth to remove all dust and debris. This step is crucial for achieving a smooth finish.
3. Choose a Finish: Select a suitable finish such as polyurethane, lacquer, or tung oil. For a glossy look, consider a spray finish. For a more natural appearance, use oil-based finishes.
4. Apply the Finish: Using a clean brush or cloth, apply your chosen finish evenly over the surface, ensuring to fill engravings and cover all areas. Follow the manufacturer’s instructions regarding application and drying times.
5. Sand Between Coats: If applying multiple coats, lightly sand between each coat once it has dried to ensure proper adhesion.
6. Final Coat: After the last coat, allow the frame to cure fully before using or displaying it.

This will provide protection against moisture, dirt, and wear while enhancing the beauty of your engraving.