## Common ground
All options are types of sign posts, defined by their material or functional technology.
## Options at a glance
**3919,3920,3921,3926.90 – Plastic**
- **Defining trait:** Made primarily from synthetic plastic materials (e.g., polyethylene, PVC).
- **Typical examples:** Roadside traffic signs, temporary directional markers, garden signs.
- **Best fit when:** The sign is lightweight, weather-resistant, and mass-produced.
**4421.99 – Wood**
- **Defining trait:** Constructed from natural wood or wood-based composites.
- **Typical examples:** Rustic trail signs, historical markers, garden plaques.
- **Best fit when:** A natural, traditional appearance is desired; low-tech or decorative use.
**6914.10 – Porcelain/China**
- **Defining trait:** Made from vitrified ceramic with a glazed, durable surface.
- **Typical examples:** High-end architectural signs, museum plaques, heritage markers.
- **Best fit when:** Long-lasting, elegant, and highly resistant to weathering.
**6914.90 – Ceramic**
- **Defining trait:** Made from non-vitrified or semi-vitrified clay-based material.
- **Typical examples:** Decorative yard signs, garden markers, artistic installations.
- **Best fit when:** A handmade or artistic look is needed; less durable than porcelain.
**7020.00 – Glass**
- **Defining trait:** Made from transparent or translucent glass, often etched or printed.
- **Typical examples:** Elegant storefront signs, museum displays, modern directional signs.
- **Best fit when:** A clear, reflective, or decorative surface is required.
**8310.00 – Base Metal**
- **Defining trait:** Constructed from iron, steel, aluminum, or other non-precious metals.
- **Typical examples:** Highway signs, industrial warning signs, street name markers.
- **Best fit when:** High durability and structural strength are needed.
**8531.20 – Digital**
- **Defining trait:** Uses electronic displays (LEDs, screens) for dynamic content.
- **Typical examples:** Electronic road signs, variable message signs (VMS), smart traffic signals.
- **Best fit when:** Real-time updates or changing information are required.
**9405.6X – Illuminated**
- **Defining trait:** Equipped with built-in lighting (LEDs, bulbs) for visibility at night.
- **Typical examples:** Nighttime road signs, illuminated parking signs, safety markers.
- **Best fit when:** The sign must be visible in low-light conditions.
## Key differences
| Option | Material | Function | Technology | Durability |
|--------|----------|----------|------------|------------|
| Plastic | Synthetic | Static | None | Medium |
| Wood | Natural | Static | None | Low–Medium |
| Porcelain | Ceramic | Static | None | High |
| Ceramic | Clay-based | Static | None | Low |
| Glass | Transparent | Static | None | Medium (fragile) |
| Base Metal | Metal | Static | None | Very high |
| Digital | Mixed | Dynamic | Electronic | High |
| Illuminated | Mixed | Static/Active | Lighting | High |
## How to choose
- Is the sign made of plastic? → 3919,3920,3921,3926.90
- Is it made of wood? → 4421.99
- Is it glazed and hard, like a tile? → 6914.10 (porcelain)
- Is it earthenware or non-glossy ceramic? → 6914.90
- Is it transparent or reflective? → 7020.00
- Is it metal (iron, steel, aluminum)? → 8310.00
- Does it show changing text or images electronically? → 8531.20
- Is it lit up at night? → 9405.6X
## Overlaps & pitfalls
A sign can be both **digital** and **illuminated** (e.g., LED display with backlight).
A **metal sign** may also be **illuminated** or **plastic-coated**.
If multiple traits apply, prioritize the **main function**:
- Use **8531.20** for digital content.
- Use **9405.6X** if lighting is the key feature (even if not digital).
- If unclear, choose based on the product’s **primary purpose or defining characteristic**