Same process as for wood puzzles EXCEPT:
- Use quality mat board obtained from art supply store in place of plywood.
- For missing knobs, do not use Plastic Wood; prepare and trace hole on mat board as if replacing a large wooden knob (Par. VII.B).
- If top edges of existing pieces in puzzle are rounded by the die cutting process, after cutting replacement piece or knob, use needle file to round top edges of new piece or knob to match other pieces BEFORE coloring. Then color right over entire piece and rounded edges.
- Use water more sparingly in coloring process. Do not soak piece. Bent or warped pieces can be straightened in vise or with weights or with fingers.