Signage & LED Glossary

Backlit

A display lit from behind a graphic or acrylic panel, giving even, soft illumination (typical of light boxes). Contrast with edge-lit.

CRI (Color Rendering Index)

How accurately a light source shows object colors, 0–100. Retail and jewelry displays want CRI 80+ so products look true.

DDP (Delivered Duty Paid)

A trade term where the seller delivers to the buyer’s door, duties and taxes paid. See also EXW.

Edge-lit

LEDs sit on the panel edge and light travels through a light-guide panel (LGP). Enables very thin profiles. Contrast with backlit.

EXW (Ex Works)

A trade term where the buyer collects goods at the factory; the buyer controls freight and risk. See also DDP.

IP rating (Ingress Protection)

A two-digit code for dust/water resistance. IP20 = indoor dry; IP65 = dust-tight and water-jet resistant for outdoor use.

LGP (Light Guide Panel)

The acrylic sheet that distributes edge LED light evenly across a panel. Virgin material (e.g. Mitsubishi) stays clear; recycled LGP yellows.

MOQ (Minimum Order Quantity)

The smallest order a supplier will accept. Low MOQ (1 unit) lets buyers pilot before a full roll-out.

Nits (cd/m²)

A measure of display brightness. Indoor signs ~800–1500 nits; window-facing ~2000+; outdoor ~3000+.

OEM / ODM

OEM = build to your design; ODM = customize the supplier’s existing design. Both are common for private-label signage.

PWM dimming

Pulse-width modulation — flicker-free brightness control. Smooth, even dimming without color shift.

RoHS

Restriction of Hazardous Substances — an EU directive limiting lead, mercury and similar in electronics. Standard for EU-bound displays.

SMD (Surface-Mount Device)

The LED package type. SMD 2835 / 3014 are common in signage for efficiency and even light.

UL / ETL

US safety-certification marks for electrical products. UL-listed drivers are expected for US-bound signs.

CE

The EU conformity mark covering safety, health and environmental requirements. Paired with RoHS for EU imports.

Planning a purchase? Use the LED Signage Procurement Checklist to brief a factory, or read our China sourcing guide.