Walk through any grow-tent factory and you will see two reflective patterns on the rolls: a small diamond emboss and a square grid. Buyers often treat them as interchangeable. They are not, and the difference matters more for light distribution than for the headline reflectivity figure.
What the emboss actually does
A perfectly flat mirror film returns light in one direction. Point a lamp at it and you get a bright hot spot on the far side of the tent and dimmer edges. Embossing breaks that single reflection into thousands of tiny facets that each send light in a slightly different direction. The total amount of light returned is almost the same; what changes is where it lands.
The diamond pattern uses facets set at alternating angles, so reflected light spreads in four directions at once. The grid pattern uses a square relief that spreads light mainly along two axes. In practice, diamond gives the more even canopy illumination and is the default choice for tents where plants sit close to the walls. Grid gives a flatter, slightly more mirror-like appearance and is preferred by some brands for the look, and for rooms where light is coming from many fixtures anyway.
Reflectivity is not the deciding factor
Both patterns are made from the same metallised film, so their total reflectivity is within a few percent of each other. Do not choose on that number alone. Choose on:
- Uniformity at the canopy. Diamond spreads more evenly; grid is more directional.
- Appearance. Grid reads as more technical; diamond as softer.
- Hot-spot risk. Diamond reduces it further, which matters with a single powerful fixture.
- Scrim and second face. These affect durability and light-proofing and are chosen separately from the pattern.
Where satin fits
A third option, a fine satin emboss, sits between a flat mirror and a diamond. It is used where a brighter, more mirror-like interior is wanted without a full hot spot, for example in propagation tents and light boxes.
How to decide
If you are unsure, ask for A4 swatches of each pattern on the same scrim and second face, hang them side by side under your fixture and photograph the wall opposite. The difference is obvious in a photo and hard to describe in words. Then specify pattern, scrim weight, second-face colour and roll width in the same order on every purchase order, so the factory never has to guess.
We supply both patterns, plus satin, as roll goods laminated to woven scrim. Request swatches and tell us the fixture you use and the tent size; we will send the two most likely candidates.