The working principle of laser engraving machine is different from that of mechanical engraving machine. Laser engraving machine realizes the engraving of two-dimensional code by laser beam cutting; Mechanical machines are carved by cutting tools, so they have different processing methods in processing materials. Laser engraving QR code For example, the most commonly used materials for laser cutting and engraving are logs. Light colored wood such as birch, cherry and maple can be easily vaporized by laser, so it is more suitable for QR code carving. Each kind of wood sign has its own characteristics. Some are dense, such as hardwood, which requires greater laser power when carving or cutting two-dimensional code. We suggest to study the properties of unfamiliar wood before carving. In fact, there is not much difference between carving on plywood and carving on wood, but it should be noted that the carving depth of QR code should not be too deep. The edge of the cut plywood will also be as black as wood. The key is to verify the carving parameters repeatedly if it depends on which kind of wood the plywood is made of.