White vs Clear Greenhouse Film: How to Choose

White vs clear greenhouse film is a choice about the light your crop needs, not simply the color of the roll. Start with the growing season and crop, then compare the proposed films' measured light transmission and diffusion. A translucent white cover, a light-diffusing growing film and an opaque blackout cover are not interchangeable.

This guide is for commercial growers and greenhouse buyers comparing flexible covers. For available film families and project requirements, see our commercial greenhouse film options.

First, establish what “white greenhouse film” means

Before comparing quotations, ask the supplier whether “white” describes a light-transmitting growing cover, an overwintering cover or a light-blocking material. Request the exact product grade and intended application. A color name alone does not tell you how much useful light will reach the crop.

Keep three questions separate:

• Transmission: how much light passes through the material?
• Diffusion: how is the transmitted light scattered?
• Light exclusion: is the material intended to block light rather than serve as the normal growing cover?

The NSW Department of Primary Industries explains that diffusing covers scatter incoming light and that films can contain different functional additives. That supports comparing optical performance, not assigning one specification to every film of the same color. Source: greenhouse covering materials.

How to compare white and clear film for your project

Production during a low-light season

Ask which proposed grade delivers the higher measured transmission under a comparable test. Do not reject a diffusing grade solely because it looks less transparent, or assume that every clear grade delivers the same result. Put your location and planting dates in the request.

Strong sunlight and uneven illumination

Ask for a light-diffusing option and its transmission data together. Describe the problem you are trying to solve: strong shadows, uneven crop development or excessive exposure. A film recommendation should also consider the greenhouse's ventilation and shading arrangements.

Seasonal plant protection rather than active crop production

State that purpose explicitly. A cover offered for overwintering should not be substituted into a year-round production specification merely because both products are white.

Photoperiod control or darkness

Request a purpose-designed light-exclusion specification. Do not treat ordinary translucent white film as a verified blackout material.

These are questions for selecting a grade, not fixed prescriptions for every crop. If your team has an agronomist or greenhouse designer, include their light and climate targets in the comparison.

Where does diffused greenhouse plastic fit?

Diffusion describes an optical property; it is not a separate color category. A useful buying comparison records both light transmission and the supplier's stated diffusion or haze result, with the measurement method. Avoid treating those labels as interchangeable numbers when the test bases differ.

Wageningen University's LightLab measures transmission, reflection, scattering, thermal properties and condensation behavior, including dry and wet conditions. Its approach illustrates why a photograph or a single “high diffusion” label is not enough to compare technical offers. Source: WUR LightLab.

For a purchasing shortlist, give each candidate a separate line for:

• Grade code, material, nominal thickness and tolerance.
• Light-transmission value, wavelength range and test method.
• Diffusion or haze value and the method used.
• Whether the reported sample was dry or wet and whether it represents one layer.
• Additional functions, their intended duration and their limitations.

If a field is missing, mark it “not supplied.” Do not turn missing data into zero performance or fill the gap with figures from a competing manufacturer's product.

Does white film automatically make a greenhouse cooler?

No color label can guarantee the operating temperature of a greenhouse. Treat daytime exposure, ventilation, shading and nighttime heat retention as separate parts of the design. The NSW covering-material guidance distinguishes light-diffusing functions from additives affecting heat loss; one should not be used as a substitute for the other.

For a hot-site quotation, describe when overheating occurs and which cooling measures are available. Ask the supplier to identify the relevant optical and thermal properties of the proposed grade. Avoid accepting an unexplained claim such as “white is always cooler.”

Do not turn research results into a yield guarantee

Research on diffuse greenhouse coverings can help explain the value of studying light distribution. It does not establish a guaranteed yield increase for an untested film. A Wageningen study of five businesses compared diffuse and clear glass greenhouses and corrected for other production factors. Its results should not be presented as a performance claim for a particular polyethylene roll. Source: WUR research on diffuse greenhouse coverings.

When a supplier claims a production benefit, ask which crop, covering material, climate and comparison treatment were used. Keep a research result and a product acceptance specification in separate parts of the order file.

A practical request to send with your inquiry

You do not need to know every optical term before asking for help. Start with the information below and identify the unknowns:

We need a greenhouse cover for [crop] in [country/region], used from [month] to [month]. Our main concern is [low light / uneven illumination / heat / another issue]. The structure is [type and dimensions], with [ventilation and shading arrangements]. Please identify a suitable film grade and provide comparable transmission and diffusion data, available dimensions, additional functions and quotation terms. Estimated quantity: [rolls or area].

This is a reusable inquiry template, not a customer case or a confirmed product specification. If dimensions are already known, include finished covering width and roll length. If not, send the structure drawing instead of guessing.

Frequently asked questions

Is clear greenhouse film always the better choice in winter?

Do not decide by appearance alone. Compare the actual grades' transmission data and the crop's needs during that season. “Clear” is a useful description, but it is not a complete light-performance specification.

Is white greenhouse film the same as blackout film?

No. Confirm whether the product transmits light or is intended for light exclusion. Require the appropriate technical information for that application before ordering.

Should I choose PE or PO first?

Define the project requirements and then compare the proposed grades. The material-family name does not, by itself, establish color, diffusion or every additive function. Our PE vs PO greenhouse film guide explains that separate decision.

Can I request a quotation before deciding between white and clear?

Yes. Send your crop, location, growing season, structure dimensions and approximate quantity. State the problem you want to address, and ask which options can be supplied with supporting technical information.

Discuss the cover before confirming the roll

Use our greenhouse film product page to start a project inquiry. Ask about the grade, optical data and functions available for your application; availability and final values must be confirmed in the quotation.