How do I make a layered sign with separate cut-out letters glued to a backer?

What the project is

A layered sign is not carved from one board. Each visual layer is cut from its own sheet, finished separately, then glued up. The machining is almost all Profile toolpaths. The skill is in organizing the layers and getting the pieces back into the positions they had on screen.

Steps

1. Design the finished sign once, at full size. Put the backer outline, the lettering and artwork, and any frame on separate layers so you can show one physical layer at a time.
2. One job or sheet per material. A published build used 1/2 inch PVC for the backer and 3/4 inch PVC for the frame parts. Each thickness needs its own material setup, so measure each sheet.
3. Nest the loose parts. Copy the letters to their sheet and use Nest Parts to save material. Keep the original, un-nested layout untouched: it is your assembly map.
4. Toolpaths. Profile, Machine Vectors Outside, for letters and backer. Small letters need tabs or a sticky hold-down. The published build held the sheet with painter's tape on both the material and the spoilboard, joined with super glue.
5. Finish before assembly. Ease edges (the example used a 1/8 inch roundover), then paint each layer its own color while the parts are apart. That is what gives the crisp two-color look with no masking.
6. Register the parts. For large pieces, take positions from measurements in the design and use a straight reference line across the backer. For small pieces, export the layout from the software as a full-scale PDF, print it, lay the parts face up on the print, bridge them with painter's tape, flip the taped group, glue, and peel the tape.
7. Glue. The example used gel super glue in dots, not lines, so nothing squeezes out past the letter edge.

Pro tips

• Thin strokes snap when you pry parts off tape. Choose bold fonts for cut-out letters.
• Cut a spare of the smallest letters. They are the ones that get lost or broken.
• See the entries on Nest Parts and on holding small parts for the details of each step.