Polycarbonate Light Diffuser Sheets for LED Lighting
HSQY PLASTIC manufactures and supplies polycarbonate diffuser sheets for LED panel lights, linear luminaires, downlights, ceiling lights, office lighting, industrial lighting, advertising light boxes, illuminated signs and customized lighting covers.
Also known as PC light diffuser sheet, LED diffuser panel, opal polycarbonate sheet, light-diffusing polycarbonate sheet or polycarbonate lighting lens, the material is designed to scatter concentrated LED light into a softer and more uniform illuminated surface.
HSQY's current product family includes approximately 0.5–12 mm thickness, standard widths of approximately 1220, 1560, 1820 and 2100 mm, opal-white and customized translucent colors, and optical grades providing approximately 82%–88% visible-light transmission with 90%–94% haze.
The ideal diffuser is not simply the sheet with the highest light transmission. A successful luminaire must balance transmission, haze, LED hiding power, diffusion, brightness uniformity, surface appearance and mechanical requirements.
What Is a Polycarbonate Diffuser Sheet?
A polycarbonate diffuser sheet is a translucent PC material engineered to scatter light passing through the sheet rather than allowing the light source to remain sharply visible.
The diffusion effect can be created using light-scattering additives distributed through the polycarbonate resin, a matte or frosted surface texture, or a combination of internal diffusion and surface texture.
When properly matched to the LED layout, the diffuser helps reduce visible LED dots, bright lines, glare and local hotspots while maintaining useful luminous output.
Unlike clear polycarbonate, the purpose of diffuser-grade PC is not maximum transparency. Instead, it is engineered to create a controlled balance between light transmission and light scattering.
Polycarbonate Diffuser Sheet Specifications
| Product | Polycarbonate Light Diffuser Sheet / LED Diffuser Panel |
| Material | Polycarbonate / PC |
| Featured Thin Gauges | 0.5 mm and 1.0 mm |
| Available Thicknesses | Approximately 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 10 and 12 mm |
| Standard Widths | Approximately 1220, 1560, 1820 and 2100 mm |
| Custom Dimensions | Custom width, length and cut-to-size panels subject to production requirements |
| Standard Color | Opal white |
| Custom Colors | Customized white tone and application-specific translucent colors subject to technical confirmation and MOQ |
| Surface | Matte/Matte, Glossy/Matte, Fine Matte, Frosted and customized textures |
| Light Transmission | Approximately 82%–88% for current listed optical grades |
| Haze | Approximately 90%–94% for current listed optical grades |
| Optical Customization | Transmission, haze, diffusion, LED hiding power, white tone and surface texture |
| Indoor Grade | Available for LED luminaires, panel lights, ceiling lights, light boxes and displays |
| Outdoor Grade | UV-stabilized grades can be evaluated for outdoor applications |
| Flame-Retardant Grade | Available only when the required formulation, thickness and fire-test rating are specified and confirmed |
| Processing | Cutting, CNC routing, drilling, punching, bending, thermoforming and printing after process validation |
| Main Applications | LED panel lights, linear luminaires, ceiling lights, downlights, light boxes, signs, displays and customized lighting covers |
Light transmission and haze should be confirmed using the exact production sheet. Optical values can change with thickness, diffusion formulation, color and surface texture.
Light Transmission, Haze and LED Hiding Power
Three concepts are particularly important when selecting an LED diffuser: light transmission, haze and LED hiding power.
| Optical Property | What It Means | Why It Matters |
| Light Transmission | Percentage of incident visible light that passes through the diffuser | Influences luminaire output and efficiency |
| Haze | Degree to which transmitted light is scattered | Higher scattering generally produces a softer, more diffused appearance |
| LED Hiding Power | Ability of the finished optical system to conceal individual LED dots or lines | Determines whether the visible surface looks uniform rather than showing bright points |
| Uniformity | Consistency of brightness across the visible illuminated surface | Important for panel lights, light boxes and architectural lighting |
Is Higher Light Transmission Always Better?
No. The highest-transmission diffuser is not automatically the best material for every LED fixture.
A very transparent diffuser can provide high luminous output but may reveal individual LEDs or create visible bright spots. Increasing diffusion can improve LED hiding and surface uniformity but may reduce total transmitted light.
The correct specification balances sufficient luminous efficiency with the required diffusion and LED-hiding performance.
Why High Haze Does Not Automatically Eliminate LED Hotspots
Haze is an important optical parameter, but it does not independently determine whether individual LEDs will remain visible.
Final hotspot performance also depends on:
For this reason, HSQY recommends evaluating diffuser samples using the customer's actual LED module and fixture geometry before approving mass production.
Internal Diffusion vs. Surface Diffusion
| Diffusion Method | Description | Selection Consideration |
| Internal Diffusion | Light-scattering particles are incorporated into the PC resin | Diffusion occurs throughout the material thickness |
| Surface Diffusion | Matte, frosted or textured surfaces scatter incident light | Surface appearance and glare can be adjusted through texture |
| Combined Diffusion | Internal scattering is combined with a diffusing surface | Useful when stronger LED hiding and controlled surface appearance are required |
Matte/Matte vs. Glossy/Matte Diffuser Sheets
| Surface | Characteristics | Typical Selection Direction |
| Matte / Matte | Textured low-reflection surface on both sides | Lighting covers where a uniformly soft appearance is required from both surfaces |
| Glossy / Matte | One smoother surface combined with one diffusing matte surface | Designs requiring a smoother visible face or different inside/outside surface behavior |
| Frosted / Fine Matte | Different levels of surface micro-texture | Custom optical and decorative requirements |
How to Choose Polycarbonate Diffuser Sheet Thickness
Thickness affects rigidity, weight, forming capability and optical behavior. The following ranges are general selection directions rather than fixed optical specifications.
| Thickness | General Selection Direction |
| 0.5 mm | Lightweight LED covers, panel lights, light boxes and formed thin covers |
| 1.0 mm | Common balance of rigidity, weight and optical performance for LED panels and luminaires |
| 1.5–3.0 mm | Larger lighting covers, light boxes, ceiling panels and more rigid diffuser components |
| 4–6 mm | Structural lighting covers, architectural panels and fabricated diffuser components |
| 8–12 mm | Specialized thick diffuser panels and fabricated architectural-lighting components |
0.5mm vs. 1mm Polycarbonate Diffuser Sheet
| Feature | 0.5mm | 1mm |
| Rigidity | More flexible | Greater rigidity |
| Weight | Lower | Higher |
| Forming | Suitable for many thin formed covers | Provides greater finished-part stiffness |
| Selection | Compact lightweight fixture designs | Larger panels or applications requiring greater panel rigidity |
Thickness alone does not determine diffusion quality. Compare the actual optical grade at the required thickness using your LED fixture.
Diffuser-to-LED Distance and LED Pitch
The distance between the diffuser and LED board is one of the most important luminaire-design variables.
If LEDs are closely spaced and the optical distance is relatively large, a higher-transmission diffuser may provide sufficient hiding performance.
If LEDs are widely spaced or positioned very close to the diffuser surface, stronger diffusion or another optical design adjustment may be required to hide visible hotspots.
When requesting an optical recommendation, provide the LED pitch and the distance from the LED emitting surface to the diffuser.
Polycarbonate Diffuser Sheets for LED Panel Lights
LED panel lights require a broad, visually uniform illuminated surface. Polycarbonate diffuser sheets can be used in both edge-lit and direct-backlit panel designs.
The appropriate diffuser specification depends on LED arrangement, light-guide or reflector design, optical distance, target lumen output, panel thickness and required surface appearance.
Polycarbonate Diffusers for Linear Lighting
PC diffuser sheets can be fabricated or formed into covers for linear LED luminaires, suspended office lighting, under-cabinet lights, commercial strips and industrial linear fixtures.
Long linear fixtures should consider diffuser rigidity, deflection, fixing method and thermal expansion in addition to optical performance.
Polycarbonate Diffusers for Downlights and Ceiling Lights
Thin PC diffuser sheets can be cut or thermoformed into round, square and customized covers for downlights, flush ceiling lights and decorative luminaires.
For shaped covers, optical properties should be evaluated after forming because stretching and geometry can change local sheet thickness and light distribution.
PC Diffuser Sheets for Light Boxes and Signs
Opal polycarbonate diffuser sheets can help distribute backlighting across advertising light boxes, illuminated signs, menu boards, retail displays and backlit graphics.
Signage applications should consider light-box depth, LED spacing, graphic opacity, required brightness and whether the diffuser is used as the visible face or behind a printed panel.
Industrial and Public-Area Lighting
Polycarbonate is often considered where the lighting cover requires greater toughness than a more brittle transparent material.
Applications can include factories, warehouses, stations, schools, elevators, transport facilities and other high-traffic areas.
Where impact, flame or transportation standards apply, the exact test method, material grade and sheet thickness should be confirmed before specification.
Polycarbonate vs. Acrylic vs. PS Diffuser Sheet
| Feature | Polycarbonate | Acrylic / PMMA | Polystyrene / PS |
| Impact Performance | High | Lower than PC | Lower and more suitable for protected indoor applications |
| Optical Performance | Good balance of diffusion, output and durability | Excellent optical appearance can be achieved | Useful for cost-sensitive lighting applications |
| Forming Capability | Good | Good with suitable process | Application dependent |
| Outdoor Application | Requires suitable UV-stabilized PC grade | Weather-resistant PMMA grades are widely available | Primarily selected for protected indoor applications unless specially modified |
| Typical Selection Priority | Durability, impact resistance and forming flexibility | Optical performance and surface appearance | Cost-sensitive indoor lighting |
Indoor vs. Outdoor Polycarbonate Diffuser Sheet
Standard indoor diffuser sheet should not automatically be specified for long-term outdoor exposure.
| Application | Material Consideration |
| Indoor LED Panel | Standard optical diffuser grade can be evaluated |
| Indoor Light Box | Select primarily according to diffusion, brightness and impact requirements |
| Outdoor Sign | UV-stabilized grade and weathering requirements should be specified |
| Outdoor Architectural Luminaire | UV, heat, environmental exposure and fixture sealing conditions should be evaluated together |
Flame-Retardant PC Diffuser Sheet
Standard diffuser sheet and flame-retardant diffuser sheet should not automatically be treated as the same grade.
If a lighting fixture requires UL 94, railway fire testing or another flammability classification, provide the exact test standard, required rating and finished sheet thickness.
A fire rating achieved by one polycarbonate formulation at one thickness should not automatically be applied to every HSQY diffuser sheet.
Does a Diffuser Sheet Determine UGR?
A diffuser can influence glare and luminance distribution, but UGR is a property of the complete luminaire and lighting installation rather than a standalone sheet specification.
UGR performance depends on luminaire dimensions, luminous intensity distribution, installation height, room geometry, observer position and surrounding luminaires.
If a project requires UGR<19 or another glare target, test the complete luminaire using the selected diffuser rather than describing the diffuser sheet itself as a guaranteed UGR product.
Color Temperature and Color Shift
Diffuser formulation, white tone and thickness can cause small changes in the perceived color of transmitted LED light.
Applications with strict CCT, chromaticity or color-rendering requirements should evaluate the finished luminaire using the final diffuser sheet and LED source.
Thermoforming Polycarbonate Diffuser Sheet
Suitable PC diffuser sheets can be thermoformed into curved lighting covers, domes, lenses and customized luminaire components.
Forming performance depends on material grade, sheet thickness, drying, heating profile, mold geometry and draw depth.
Stretching during thermoforming can change local thickness, haze and light transmission, so optical testing should be repeated on the finished formed component when uniform lighting is critical.
Cutting and Fabricating PC Diffuser Sheets
Polycarbonate diffuser sheets can be processed using suitable plastic-fabrication methods including cutting, CNC routing, drilling, punching and forming.
HSQY can discuss custom cut-to-size diffuser panels and fabricated parts based on drawings or physical samples.
Keep protective film on the sheet during machining where practical to reduce scratches and contamination.
Diffuser Sheet vs. Clear Polycarbonate Sheet
| Feature | PC Diffuser Sheet | Clear PC Sheet |
| Main Purpose | Scatter and distribute light | Maximum visibility and direct transmission |
| Appearance | Opal, translucent or frosted | Transparent |
| LED Hiding | Designed to reduce visibility of LEDs | Individual LED sources remain more visible |
| Typical Application | Lighting and backlit displays | Glazing, machine guards and protective covers |
For clear structural and protective applications, review our Solid Polycarbonate Sheet range.
PC Diffuser Sheet vs. Light Diffusing Polycarbonate Film
Thick diffuser sheet and thin light-diffusing PC film serve different application needs.
| Feature | PC Diffuser Sheet | Light Diffusing PC Film |
| Structure | Semi-rigid or rigid panel | Thin flexible or semi-rigid film |
| HSQY Positioning | Approximately 0.5–12 mm lighting panels and covers | Thin film applications including approximately 0.125–1.0 mm selected products |
| Typical Application | Luminaires, panel lights, light boxes and formed light covers | Backlight modules, illuminated keyboards, displays and electronic optical systems |
Thin-film projects can also review our Polycarbonate Film range.
Custom Optical Performance
Different lighting fixtures require different combinations of brightness and diffusion. HSQY can evaluate customized optical specifications according to the customer's fixture design.
Custom variables can include:
How to Select a Polycarbonate Diffuser for Your LED Fixture
1. Define the Lighting Application
Specify LED panel light, linear luminaire, downlight, ceiling light, light box, sign, display or another lighting application.
2. Provide LED Pitch
Provide center-to-center LED spacing because widely spaced LEDs are generally more difficult to hide.
3. Provide Optical Distance
Specify the distance between the LED emitting surface and diffuser panel.
4. Define Light-Output Requirements
Provide target luminaire output or transmission requirement if known.
5. Define LED Hiding Requirements
Confirm whether the visual surface must completely hide LED dots or whether slight source visibility is acceptable.
6. Select the Thickness
Choose thickness according to optical requirements, panel dimensions, rigidity, weight and forming process.
7. Select the Surface
Specify Matte/Matte, Glossy/Matte, frosted or another required surface texture.
8. Confirm Indoor or Outdoor Use
Outdoor applications should specify UV-stabilization and expected weather exposure.
9. Confirm Fire Requirements
If a specific flammability standard is required, provide the test method, required classification and sheet thickness.
10. Confirm Fabrication
Specify whether the sheet will be cut, drilled, bent, thermoformed, punched or printed.
11. Test Samples in the Final Fixture
Compare candidate grades using the actual LED board, power setting, reflector, optical distance, frame and final installation geometry.
Recommended Diffuser Sample Testing
Sample testing should evaluate the complete lighting system rather than the sheet in isolation.
Custom Polycarbonate Diffuser Sheet Manufacturing
HSQY supports custom diffuser projects for LED lighting manufacturers, luminaire manufacturers, signage companies, lighting-component distributors and industrial fabricators.
Custom options can include:
0.5–12 mm product range
Custom sheet thickness
Custom width and length
Cut-to-size diffuser panels
Customized light transmission
Customized haze
Customized diffusion and hiding power
Custom opal-white tone
Custom translucent colors
Matte/Matte surface
Glossy/Matte surface
Fine matte and frosted textures
UV-stabilized grade
Application-specific flame-retardant grade
CNC cutting and drilling
Thermoformed lighting covers
Protective film
OEM and export packaging
Polycarbonate Diffuser Sheet Quality Control
Important inspection and sample-approval parameters can include:
Thickness and thickness tolerance
Sheet width and length
Light transmission
Haze
Diffusion consistency
LED hiding performance
White-tone consistency
Surface texture
Sheet flatness
Visual defects
Protective-film condition
UV stabilization where required
Flammability documentation where specified
Cutting and fabrication performance
Thermoforming performance where required
Certifications and Test Documents
Available documents can depend on the selected polycarbonate formulation and project specification.
When a project requires restricted-substance reports, optical test data, flame-retardant testing, quality-management documents or another certification, confirm that the document applies to the exact grade, thickness, color and surface being purchased.
SGS or another third-party report should be described according to its actual testing scope rather than treated as a universal certification for optical, outdoor, fire or electrical performance.
Packing and International Shipping
Polycarbonate diffuser sheets can be supplied with protective film and export packaging according to sheet size, thickness, surface and shipment requirements.
Cut samples can be packed separately for optical evaluation, while commercial sheets can be protected using PE film, kraft paper, cartons or palletized packaging according to order configuration.
Why Choose HSQY as Your Polycarbonate Diffuser Sheet Manufacturer?
Broad Thickness Range: Current diffuser products cover thin 0.5 mm and 1 mm sheets together with additional options up to approximately 12 mm.
Wide Sheet Widths: Current standard widths include approximately 1220, 1560, 1820 and 2100 mm.
Defined Optical Grades: Current listed grades include approximately 82%–88% transmission and approximately 90%–94% haze.
Custom Optical Performance: Transmission, haze, diffusion level, LED hiding power and white tone can be evaluated according to fixture requirements.
Multiple Surface Options: Matte/Matte, Glossy/Matte, fine matte, frosted and custom textures are available according to product specification.
Indoor and Outdoor Solutions: Standard indoor products and application-specific UV-stabilized outdoor grades can be evaluated.
Fabrication Support: Cutting, routing, drilling, punching and thermoforming can be discussed for customized lighting components.
Optical Sample Testing: Customers can compare samples in the final LED fixture before selecting a commercial grade.
Information Needed for a PC Diffuser Sheet Quote
| Application | LED panel, linear light, ceiling light, downlight, light box, signage or other application |
| Thickness | Required thickness or current material thickness |
| Dimensions | Required sheet width × length or finished cut size |
| Light Transmission | Target value if specified |
| Haze | Target value if specified |
| LED Pitch | Center-to-center distance between LED sources |
| Optical Distance | Distance between LED source and diffuser |
| Hiding Requirement | Fully hidden LED dots or acceptable source visibility |
| Surface | Matte/Matte, Glossy/Matte, frosted or other texture |
| Color | Standard opal, target white tone or customized translucent color |
| Indoor / Outdoor | Indoor use or outdoor UV exposure |
| Fire Requirement | Required fire-test standard and classification where applicable |
| Processing | Cutting, drilling, punching, bending, forming or other processing |
| Quantity | Trial quantity, regular order quantity and estimated annual demand |
| Destination | Destination country and port |
Polycarbonate Diffuser Sheet FAQ
What is a polycarbonate diffuser sheet?
A polycarbonate diffuser sheet is a translucent PC panel engineered to scatter light and create a softer, more uniform illuminated surface while reducing visible LED dots and hotspots.
What are PC diffuser sheets used for?
Common applications include LED panel lights, linear luminaires, downlights, ceiling lights, office lighting, light boxes, illuminated signs and backlit displays.
What thicknesses does HSQY offer?
HSQY's current diffuser range includes featured 0.5mm and 1mm sheets together with additional thicknesses up to approximately 12mm.
What widths are available?
Current standard widths include approximately 1220mm, 1560mm, 1820mm and 2100mm. Custom cutting can also be discussed.
What is the light transmission of HSQY PC diffuser sheet?
Current listed HSQY optical grades provide approximately 82%–88% visible-light transmission. The exact value depends on thickness, color, surface and diffusion formulation.
What is the haze of HSQY diffuser sheet?
Current listed grades provide approximately 90%–94% haze. Confirm the applicable thickness and test method for the selected product.
What is the difference between light transmission and haze?
Light transmission measures how much visible light passes through the sheet, while haze measures how strongly that transmitted light is scattered.
Does higher haze hide LEDs better?
Higher haze can improve scattering, but LED hiding also depends on LED spacing, optical distance, LED power, beam angle, reflector design, thickness and diffuser formulation.
Is higher light transmission always better?
No. Higher transmission can improve luminous output but may make LED dots easier to see. The correct grade balances output efficiency with diffusion and hiding power.
Can a 90% haze sheet still show LED hotspots?
Yes. Hotspot visibility depends on the complete luminaire design. A high-haze sheet cannot compensate for every LED spacing and optical-distance configuration.
Is 0.5mm or 1mm PC diffuser better?
A 0.5mm sheet is lighter and more flexible, while a 1mm sheet provides greater rigidity. Optical performance should be compared using the actual grade and fixture design.
What is the difference between Matte/Matte and Glossy/Matte?
Matte/Matte uses a low-reflection textured finish on both surfaces, while Glossy/Matte combines one smoother face with one matte diffusing face.
Is polycarbonate better than acrylic for LED diffusers?
Polycarbonate is generally selected when impact resistance, toughness and forming capability are important. Acrylic can provide excellent optical appearance and surface hardness. The better material depends on fixture requirements.
Is PC diffuser sheet better than PS diffuser sheet?
PC is generally selected for applications requiring higher impact resistance and more demanding mechanical performance. PS is often selected for cost-sensitive protected indoor lighting applications.
Can polycarbonate diffuser sheet be used outdoors?
Yes, but an application-specific UV-stabilized grade should be used for prolonged outdoor exposure. Standard indoor material should not automatically be used outdoors.
Is polycarbonate diffuser sheet flame retardant?
Flame-retardant grades can be evaluated, but the exact rating must be confirmed for the specific formulation, thickness and test standard.
Can diffuser sheet guarantee UGR<19?
No diffuser sheet alone should guarantee UGR<19. UGR depends on the complete luminaire, luminous-intensity distribution and installation environment.
Can PC diffuser sheet be thermoformed?
Yes. Suitable forming grades can be thermoformed into curved light covers after appropriate drying, heating and mold testing.
Can polycarbonate diffuser sheet be cut to size?
Yes. HSQY can discuss customized cutting, routing, drilling, punching and other fabrication according to drawings and order requirements.
Can the light transmission and haze be customized?
Yes. Transmission, haze, diffusion, LED hiding power, white tone and surface texture can be evaluated for customization subject to technical feasibility and order quantity.
Can the diffuser affect LED color temperature?
The diffuser formulation and white tone can cause a small optical color shift. Test the finished fixture when CCT and chromaticity requirements are strict.
Can HSQY match my current diffuser sheet?
HSQY can evaluate an existing physical sample together with thickness, transmission, haze, white tone and surface requirements to develop a comparable specification.
Can I request samples for LED testing?
Small sheets and cut samples can be discussed for evaluating transmission, haze, LED hiding, color, surface and fabrication performance.
What information should I provide for a quotation?
Provide application, thickness, dimensions, target transmission and haze, LED pitch, optical distance, surface, indoor or outdoor use, fabrication requirements, quantity and destination.
Request a Polycarbonate Diffuser Sheet Quote
Looking for a reliable polycarbonate diffuser sheet manufacturer, PC light diffuser supplier or customized optical diffuser for an LED lighting project?
Send HSQY your sheet thickness, dimensions, LED pitch, optical distance, target transmission, haze and estimated purchasing quantity. Our team can recommend candidate grades and provide samples for testing in your actual luminaire.
