For overseas buyers purchasing light boxes—whether for retail stores, restaurants, trade shows, or outdoor advertising—"brightness" is often the first factor that catches the eye. However, industry insiders warn that focusing solely on brightness is a common mistake that can lead to buying low-quality products: some cheap light boxes use excessive LED chips to boost brightness, but they lack proper heat dissipation, resulting in short lifespans, frequent malfunctions, or even safety hazards.

To help you make an informed decision, we’ve broken down 3 core parameters that are more critical than brightness. Mastering these will help you avoid the "low-quality light box" trap and get the best value for your investment.

Imagine this scenario: You buy a light box to display high-end clothing, but the red dress in the light looks dull and grayish—nothing like its actual vibrant shade. The culprit is likely a low Color Rendering Index (CRI), a parameter that measures how accurately a light source reproduces the true colors of objects (compared to natural sunlight).

• CRI is rated on a scale of 0-100: A CRI of 100 means the light perfectly replicates natural sunlight, while a CRI below 80 will distort colors. For most commercial scenarios (e.g., clothing stores, jewelry shops, art galleries), a CRI of Ra ≥ 90 is a must. For example, a jewelry store with a 95 CRI light box will make diamonds sparkle more brilliantly, and gold jewelry will show its true warm tone—helping attract customers and reduce returns due to "color mismatch."
• Low CRI = Hidden Costs: A light box with CRI < 70 may seem cheap upfront, but it can harm your business. A restaurant using such a light box might make food look unappetizing (e.g., green salads appear yellowish, red meats look gray), leading to fewer orders.

• Check the product specification sheet: Reputable manufacturers will clearly mark the CRI value (e.g., "CRI Ra90+"). Avoid products that only mention "high color rendering" without a specific number.
• Do a simple test: Bring a sample of the item you’ll display (e.g., a piece of fabric, a product box) and compare its color under the light box and natural sunlight. If there’s a noticeable difference, the CRI is likely too low.

Overseas buyers often use light boxes in diverse environments: outdoor billboards exposed to rain and dust, restaurant light boxes near grease and steam, or bathroom signage in humid spas. The IP (Ingress Protection) Rating—a two-digit code that indicates a device’s resistance to solids (e.g., dust) and liquids (e.g., water)—is crucial to ensuring durability.

• The first digit (0-6) = Dust resistance:
  • 0: No protection
  • 6: Totally dust-tight (ideal for outdoor or industrial areas with heavy dust)
• The second digit (0-9K) = Water resistance:
  • 4: Resists splashing water (suitable for indoor areas like retail stores)
  • 6: Resists powerful water jets (good for restaurant kitchens or car washes)
  • 8: Can be submerged in water (for special scenarios like underwater exhibits)
• Common Scenario Recommendations:
  • Outdoor advertising light boxes: Choose IP65 or higher (dust-tight + resists low-pressure water jets, e.g., rainstorms).
  • Indoor retail light boxes: IP44 is sufficient (resists splashes, e.g., accidental spills).
  • Bathroom or poolside light boxes: IP67 (dust-tight + can be submerged in 1m of water for 30 minutes).

• Look for the IP rating label: It should be printed on the light box’s housing or power cord (e.g., "IP65"). Some low-quality products fake the label—verify by checking the manufacturer’s official website or asking for a certification report (e.g., from TÜV or SGS).
• Test for basic water resistance (if possible): For small light boxes, spray a little water on the surface (avoiding the power port) and check if the light flickers or shuts off.

The power supply (also called the "driver") is the "heart" of a light box—it converts AC power to DC power for the LEDs. Many buyers ignore this component, but a low-efficiency power supply can lead to high electricity bills, overheating, and shortened LED lifespan.

• Efficiency Rating: Power supply efficiency is measured as a percentage (e.g., 85% efficiency means 85% of the input power is converted to usable light, and 15% is wasted as heat). For commercial light boxes, choose a power supply with efficiency ≥ 85% (look for labels like "85+ Efficiency").
  • Example: A 100W light box with 80% efficiency uses 125W of input power (100W ÷ 0.8 = 125W), while one with 90% efficiency uses only 111W. Over a year (12 hours/day), the 90% efficiency model saves about 150 kWh of electricity—equivalent to $20-30 in savings (based on average U.S. electricity rates).
• Safety Certifications: A high-quality power supply should have certifications like UL (U.S.), CE (EU), or PSE (Japan). These certifications ensure the power supply meets strict safety standards (e.g., overvoltage protection, short-circuit protection) and won’t cause fires or electric shocks.

• Inspect the power supply: Reputable light boxes use branded power supplies (e.g., Mean Well, Philips) with clear efficiency labels. Avoid light boxes with unbranded, "no-name" power supplies—they often cut corners on safety and efficiency.
• Calculate long-term costs: Ask the manufacturer for the light box’s "power consumption per hour" (in kWh) and multiply by your local electricity rate and daily usage time. A slightly more expensive light box with a high-efficiency power supply will save you money in the long run.

1. "Too Bright, Too Cheap": If a light box claims to have "10,000 lumens" but costs 50% less than similar products, it’s likely using low-quality LEDs or overloading the power supply. These light boxes may burn out in a few months or even emit harmful blue light.
2. No Warranty or Short Warranty: A reliable light box manufacturer will offer a 2-5 year warranty (covering LEDs, power supply, and housing). If a product only has a 3-month warranty or no warranty at all, it’s a sign of poor quality.

For overseas buyers, purchasing a light box is an investment in your business’s image and efficiency. By focusing on CRI, IP rating, and power supply efficiency—instead of just brightness—you’ll avoid the "low-quality trap" and choose a product that’s durable, energy-saving, and tailored to your needs. Whether you’re buying for a small boutique in Paris or a large outdoor billboard in New York, these parameters will help you make a smart decision.