## Common ground
All options are types of traffic signs classified by material or technology.
## Options at a glance
**3919,3920,3921,3926.90 – Made of plastic material**
- **Defining trait:** Constructed from synthetic polymers, often lightweight and weather-resistant.
- **Typical examples:** Standard road signs, temporary warning signs, reflective plastic panels.
- **Best fit when:** The sign is non-metallic, flexible, or used in temporary or mass-produced installations.
**4421.99 – Made of wood**
- **Defining trait:** Crafted from natural timber, typically for low-speed or rural areas.
- **Typical examples:** Handmade signs, historical markers, pedestrian crossing signs in villages.
- **Best fit when:** The sign is wooden, hand-carved, or used in non-highway, low-traffic zones.
**6914.10 – Made of porcelain or china**
- **Defining trait:** High-durability ceramic material, often glazed and used for permanent signage.
- **Typical examples:** Vintage traffic signs, decorative or heritage road markers.
- **Best fit when:** The sign is ceramic, glazed, and intended for long-term outdoor use in aesthetic contexts.
**6914.90 – Made of ceramic**
- **Defining trait:** Non-porcelain ceramic material, less common but used for specialized signage.
- **Typical examples:** Artistic or custom signs, niche public installations.
- **Best fit when:** The sign is ceramic but not glazed or made from porcelain.
**7020.00 – Made of glass**
- **Defining trait:** Transparent or translucent material, often used with reflective coatings.
- **Typical examples:** Reflective glass signs, decorative or illuminated displays.
- **Best fit when:** The sign is glass-based, possibly with reflective or printed elements.
**8310.00 – Made of base metal**
- **Defining trait:** Constructed from iron, steel, or other non-precious metals.
- **Typical examples:** Heavy-duty road signs, highway signage, mounting frames.
- **Best fit when:** The sign is metallic, rigid, and used in high-traffic or durable infrastructure.
**8531.20 – Digital**
- **Defining trait:** Uses electronic displays (e.g., LED screens) to show dynamic messages.
- **Typical examples:** Variable message signs (VMS), smart traffic signals, digital speed limit signs.
- **Best fit when:** The sign changes content in real time or is powered by electricity.
**9405.6X – Illuminated**
- **Defining trait:** Equipped with internal lighting to be visible at night.
- **Typical examples:** Nighttime warning signs, illuminated crosswalks, highway exit signs.
- **Best fit when:** The sign has built-in lights or is designed for low-light visibility.
## Key differences
| Option | Material | Technology | Power Source | Visibility Feature |
|-------|----------|------------|--------------|---------------------|
| 3919–3926.90 | Plastic | None | N/A | Reflective surface |
| 4421.99 | Wood | None | N/A | Natural appearance |
| 6914.10 | Porcelain | None | N/A | Glazed, durable |
| 6914.90 | Ceramic | None | N/A | Non-porcelain ceramic |
| 7020.00 | Glass | None | N/A | Transparent/reflective |
| 8310.00 | Base metal | None | N/A | Rigid, heavy-duty |
| 8531.20 | N/A | Digital display | Electric | Dynamic content |
| 9405.6X | Any | Lighting | Electric | Night visibility |
## How to choose
- Is the sign made of plastic? → 3919–3926.90
- Is it wooden? → 4421.99
- Is it glazed ceramic or porcelain? → 6914.10
- Is it non-porcelain ceramic? → 6914.90
- Is it glass-based? → 7020.00
- Is it metal (iron/steel)? → 8310.00
- Does it display changing messages electronically? → 8531.20
- Is it lit internally for night use? → 9405.6X
## Overlaps & pitfalls
A sign can be both **digital (8531.20)** and **illuminated (9405.6X)** — prioritize based on main function: if content changes dynamically, choose 8531.20; if visibility at night is key, use 9405.6X.
"Made of plastic" may include reflective or illuminated versions — check for lighting or digital features first.
No option clearly defines "reflective" — this trait is implied in many materials but not a standalone category