## Common ground
Both options involve copying paste, a substance used in printing or marking processes.
## Options at a glance
**3824.99 – Copying paste with gelatin base**
- **Defining trait:** Contains gelatin as its primary base material.
- **Typical examples:** Gelatin-based transfer pastes for art or archival copying.
- **Best fit when:** The product is primarily a paste made from gelatin, used for non-industrial marking or preservation.
**8443.91 – Inking rollers coated with copying paste**
- **Defining trait:** The copying paste is applied as a coating on a mechanical component (inking roller) for printing machines.
- **Typical examples:** Roller covers used in offset or letterpress printing.
- **Best fit when:** The paste is not sold separately but is part of a machine component used in industrial printing.
## Key differences
| Feature | 3824.99 – Gelatin base | 8443.91 – Coated inking roller |
|-----------------------|-------------------------------|--------------------------------------|
| Primary material | Gelatin | Not specified; applied to roller |
| Form | Standalone paste | Integrated into a printing part |
| Use case | Art, archival, non-industrial | Industrial printing machinery |
## How to choose
- Is the copying paste sold as a standalone product with gelatin as its main ingredient? → 3824.99
- Is the copying paste applied directly to an inking roller used in a printing machine? → 8443.91
## Overlaps & pitfalls
A product could be both a gelatin-based paste *and* used on rollers, but the key is whether it’s sold as a separate substance (3824.99) or as part of a machine component (8443.91). If unclear, prioritize based on **main function**: standalone paste vs. functional part of a printing device. Do not assume gelatin content implies industrial use