Lasers cut and engrave flat sheet materials, see one in action here:
Laser cutting uses a computer to direct light at the material to be cut. The material then melts, burns, or vaporizes leaving an edge with a high-quality finish. Check out the different edge finishes of materials here
The laser beam is guided by the lines in vector design files and Ponoko cuts on the center of the lines in your file.
The amount of material burnt away during cutting is known as kerf and on average is 0.008" (0.2mm) wide. Because the laser cuts with the power of light and materials have different melting points, there can be a small amount of variation. Our materials pages have more specific kerf averages.
The beam of light has a cone like shape, therefore edges are not always perfectly 90 degrees. This is more noticeable on thicker sheets of material.