Engravers decorate metal or glass objects using hand tools or powered devices. Examples of their work are names engraved on wristwatches, trophies, dishes, etc. They are also often able to use their own designs in their work. Mass-produced items are usually machine-engraved. Some engravers are self-employed, and some work for companies. There are many different mechanised tools used in this work, depending on whether a large area is to be sandblasted or photo-etched, for instance, or if it should be fine work done by hand tools. Etching on glass is also done using acid.