Neither white nor silver is universally the better wall lining. Compare the exact surfaces under the intended lighting and ventilation conditions. Colour alone cannot establish total reflectance, canopy uniformity, room temperature or plant growth. A sample test is more useful than a claim that one colour always wins.
What each one does with light
For silver metallised film, distinguish a mirror-like finish from a diamond or matte finish. Surface texture can change the angular distribution of reflected light, but a pattern name does not quantify total reflectance. Ask for the wavelength range, measurement method and exact sample identity.
For white film, assess diffuse reflection, gloss, opacity and total reflectance separately. A diffuse surface is not necessarily a low-reflectance one: Labsphere’s white diffuse reference materials illustrate why colour cannot establish a universal ranking. Those laboratory materials are not PET wall-lining products, and their performance must not be attributed to our films.
Heat
Do not assume that white film makes a room cooler or that silver film necessarily makes it hotter. Visible-light appearance alone is not a measurement of thermal behaviour. For a useful comparison, keep fixture power, position, ventilation, room geometry and measurement locations consistent, and record the resulting temperatures. Without a controlled comparison, we do not promise a temperature reduction for either colour.
Durability and cleaning
Cleaning and abrasion resistance depend on the exposed coating and full construction, not just colour. Ask for the permitted cleaning method and validate it on a sample with the intended detergent, contact time and handling. Do not assume that every white or metallised grade is washable.
When to choose which
- When light return is the priority: compare measured reflectance and useful light reaching the plant area under the same fixture.
- When uniformity is the priority: compare a grid of measurements at the intended canopy height rather than judging the wall by eye.
- When temperature is the concern: test the full room configuration; changing liner colour is not a substitute for validating the ventilation and heat load.
- For manufacturers buying rolls: specify each face, backing, required opacity, roll width and processing conditions. Approve a reference sample before assigning a repeat-order specification.
Running a sample test that will hold up
Hang the two swatches side by side on the same wall, under the same fixture, at the distance the finished lining will sit from the light. Fix the camera settings — exposure, white balance and ISO — before the first photograph and do not change them between swatches; an automatic camera will normalise the difference away. Take readings at the canopy height you actually grow at, not at the wall, and take them at the same points for both swatches. Record the fixture, the distance and the ambient temperature alongside the readings, so the test can be repeated when a new batch arrives.
Reading what you get
Compare the spread of readings across the canopy grid, not just the brightest point. A wall that gives the highest single reading and the widest spread is delivering a hot spot, which is usually the outcome the buyer was trying to avoid. Compare the two photographs at the same magnification for the texture that will show at eye level. Then decide, and write the winning construction — face, backing, finish and width — into the specification with the swatch reference, so the next roll is judged against the same sample.
A third option
A white face can be combined with a metallised film or another backing in a laminate. Specify each layer and validate any light-blocking or optical requirement for that exact construction. A white appearance on one face is not proof of the backing material or its performance.
We supply silver metallised film in mirror, diamond and matte finishes, white PET film, and laminates of both on woven scrim. The pair most buyers end up hanging side by side is the Fine Texture Reflective Laminate, White / Dark Back against the Fine Weave Reflective Laminate, Silver. Ask for swatches of each and test them under your own fixture.