The process of making three-dimensional relief copper lettering for hotel door numbers generally involves the following steps:
1. **Design and Drawing**: Based on the hotel’s requirements, a three-dimensional model of the door number is drawn using professional design software, with details such as font, pattern, size, and relief depth determined.
2. **Mold Making**: The designed model data is transferred to a milling machine to carve a mold on suitable materials such as wood or plaster.
3. **Casting Copper**: The copper material is heated and melted into molten copper, which is carefully poured into the mold and allowed to cool and solidify.
4. **Post-processing**: The formed copper letters are polished and smoothed to make the surface glossy; then, anti-corrosion treatment is applied; finally, they are installed on the door.