Does Shade Cloth Color Matter?

Most shade cloth I’ve seen advertised is black.I’m wondering if something like a white will improve cooling,with the same level of light penetration percentage.
Does anyone have experience using something other than the standard? Brady

No. But the percentage of shading does. Further, unless you are shading light-sensitive plants the standard shade cloths (60%-70%) shade too much.

About color: there is a common misperception that light-colored materials stay cooler than dark colored ones. This is only true for certain materials such as solid rock; e.g., basalt is denser and thus retains less heat than quartz. Humorously until lead was banned in paint (it was used to produce white color), the surface of a white color car would be hotter than a black color car in the sun. For fabrics, the amount of heat retained or reflected back by the material is due to (1) the composition of the fabric, (2) the dye (if any) used in the fabric, (3) and the reflectivity of the fabric finish.

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Brady:

I’ve used the aluminet. It’s shiny and sort of like aluminum foil woven into a shade fabric. I think it’s very effective but not nearly as durable as the black woven polypropylene I’ve also used. The aluminet is also expensive.

There would be nothing wrong with using white. I think it would be just as effective and for certain applications maybe more effective than black.

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Presently, the shade cloth I"m using is black, 50% rated and it is set up to be rolled up and down on the entire South side of a greenhouse.
One of the plants is a Passiflora edulis,grown from seed,in a pot, for two years.The plant has put on some good growth but no flowers yet.
I thought maybe the cloth might be too shading,but really needs to be used,for the sake of some other plants.
Another reason could be,the vine may need to get another year older. Brady

Depending what those other plants are, I’d choose 30%.

Richard,

Maybe I’m misunderstanding the point, but although much of the energy from the sun is in wavelengths invisible to humans, there is still a significant amount of energy in the visible spectrum. Assuming materials are the same, black materials would absorb more energy (absorbing all visible light) making the material “hotter” while white would reflect it.

Reflection is a surface property, e.g., polished vs. dull.

Two materials of different hue are never the same.

Richard,

I didn’t intend to turn the point into an either/or discussion (i.e. it has to be either color, or something else) which would cause us to fall into the “fallacy of false choice”. Of course there are many factors which would contribute to an object being “hotter” or “cooler” in sunlight (material of the object, polished vs. dull finish, etc.) My point was that color of the surface matters, and is one of the factors (a major one) when considering this issue.

More as it relates to the OPs question. Brady, it appears reflective white shade cloths may keep plants cooler than black shade cloths. According to this research linked below, the best choice to reduce heat in your building would be a reflective aluminum foil laminate (as Fruitnut mentions) or white.

“While black shades block light, they allow heat to radiate onto plants.
External screens like Svensson’s FLS are made with highly reflective
aluminum foil laminates or white films to reflect heat and light. They
protect plants from stressing under too much sun, yet allow some light
to penetrate by shading in a more efficient way.”

http://www.greenhousegrower.com/technology/equipment/black-shade-cloth-versus-reflective-screens/

Thanks for the responses.There is a lot to this.
My knowledge of the word “hue” is very limited compared to this Wikipedia explanation.

Brady

What we refer to as “Color” is actually a multidimensional phenomenon. Hue is one of the dimensions. Specifically it is the wavelength of light.

My knowledge of optics and thermodynamics comes from undergraduate and graduate degrees in Physics. I really don’t care to discuss the points I made any further.