## Common ground
Both options refer to photomask pellicles—thin, transparent films used to protect photomasks in semiconductor manufacturing.
## Options at a glance
**3926.90 – Plastic articles**
- **Defining trait:** Classified primarily by material (plastic), regardless of function.
- **Typical examples:** Plastic sheets, film covers, non-electronic plastic components.
- **Best fit when:** The pellicle is treated as a general-purpose plastic item with no functional integration into electronic manufacturing machinery.
**8486.90 – Parts of IC manufacturing machines**
- **Defining trait:** Classified by function—specifically as parts used in machines for manufacturing electronic integrated circuits.
- **Typical examples:** Components that are integral to photolithography tools, such as mask holders or alignment systems.
- **Best fit when:** The pellicle is used as a functional part within a semiconductor fabrication machine and is designed specifically for integration into such equipment.
## Key differences
| Criterion | 3926.90 – Plastic articles | 8486.90 – IC manufacturing parts |
|-------------------------|----------------------------------|----------------------------------|
| Primary classification | Material (plastic) | Function (machine part) |
| Integration with machinery | Not required | Required |
| Use context | General plastic use | Semiconductor fabrication |
## How to choose
- Is the pellicle primarily defined by its material (plastic), not its function? → 3926.90
- Is it used as a functional component in an IC manufacturing machine? → 8486.90
## Overlaps & pitfalls
A photomask pellicle may qualify under both categories: it is made of plastic (3926.90) and serves a key role in IC production machinery (8486.90). However, **the main function determines classification**. If the product’s primary purpose is to protect a photomask within a semiconductor fabrication process, **8486.90 takes priority**. If it's sold as a standalone plastic film without machine integration, use 3926.90. The wording does not specify priority—users should base choice on the product’s primary role