How To... 3D Grayscale

Introduction

This tutorial will guide you through the process of 3D grayscale engraving, also known as 3D relief engraving. This technique allows you to create depth and dimensionality in materials like wood and acrylic by varying the engraving power according to different shades of gray in an image. By following these steps, you’ll learn how to prepare your images, set up your engraving software, and achieve high-quality results.

Step 1: Prepare Your Image

1. Select an STL File or Grayscale Image

   • Look for images suitable for 3D engraving. A popular choice is an image of a bee with honeycomb.
   • Use search tools to find higher resolution images (e.g., 570x570 pixels or larger).

2. Edit the Image in Photoshop

   • Open the downloaded image in Photoshop.
   • Increase sharpness using Filter > Sharpen > Smart Sharpen.
   • Adjust the image size:
     • Set dimensions (e.g., 4x4 inches).
     • Increase resolution to 400 DPI for better detail.
   • Export the image as a PNG file (File > Export > Export As).

Step 2: Set Up LightBurn for Engraving

1. Import Your Image

   • Open LightBurn and import the PNG file.

2. Configure Image Settings

   • Double-click on the image layer and set it to grayscale.
   • Adjust DPI settings based on your machine specifications. For example, use 300 DPI for a 100-watt machine with a 1.5-inch lens.

3. Set Power Levels

   • Determine your maximum and minimum power settings:
     • Set max power (e.g., 26).
     • Identify the min power threshold (e.g., 6-8); choose a middle value (e.g., 7).
   • Ensure the line interval and scan angle are set appropriately (e.g., 180 degrees).

4. Select Material and Settings

   • Choose the material for engraving (e.g., wood or acrylic).
   • For wood, keep negative image unselected so max power engraves darker areas.
   • For acrylic, consider multiple passes at lower power to avoid burning.

Step 3: Prepare the Engraving Machine

1. Adjust Size and Speed

   • Ensure image size matches your material (e.g., increase to 5x5 inches if needed).
   • Set the engraving speed to a slower rate (e.g., 8-12 inches per second) to enhance engraving quality.

2. Run the Engraving

   • Start the engraving process and monitor for quality. Look for vertical lines as a potential issue related to speed or machine settings.

Step 4: Post-Engraving Finishing

1. Evaluate the Initial Result

   • After completing the engraving, check for depth and quality.
   • If the depth is insufficient, increase the max power setting and engrave again.

2. Final Touches

   • Lightly sand the surface using an orbital sander for a smooth finish.
   • Use low speed and light grit to avoid damaging the engraved detail.

Conclusion

By following these steps, you can effectively create stunning 3D grayscale engravings on various materials. Remember to experiment with different images, power settings, and materials to achieve the best results. Once you gain confidence with the technique, you can explore further applications like half-tone or dither engraving for unique effects. Don't forget to share your creations!