Mermet KOOLBLACK Fabrics
35 charcoal colourways in 2 designs: the dark screen that reflects the infrared instead of absorbing it.
The clearest view, without the hot fabric
A charcoal screen gives the clearest view and the least glare, because dark yarn scatters less of the light it lets past. It also absorbs the sun: a conventional charcoal E Screen absorbs more than 90% of the solar energy that reaches it and re-radiates part of that into the room. KOOLBLACK is Mermet's patented answer, developed with BASF and launched in 2012. The yarn is formulated to reflect the near-infrared part of sunlight, 64% of it against 3% for a conventional charcoal, so the fabric runs up to 15 degrees cooler and the room asks less of the air conditioning.
Mermet weaves it into two lines, 35 colourways in 2 designs. E Screen with KOOLBLACK is the 2x2 basketweave in five charcoals at 0.5%, 1%, 3%, 5% and 10%; T Screen with KOOLBLACK is the satin weave in five charcoals at 1% and 3%, with a charcoal heat-reflective street side. Everything else is unchanged: the same 36% fiberglass and 64% vinyl cloth, the same widths, the same NFPA 701 TM#1, California Title 19 and CAN/ULC-S109 listings, GREENGUARD Gold and RoHS lead free. This is our default when a client wants charcoal on hard ocean or west glass.
2 Mermet KOOLBLACK designs, 35 colourways
What the numbers say
Near-infrared reflectance
Roughly half of the sun's energy arrives as near-infrared light, invisible but felt as heat. Plain black yarn soaks it up. Mermet's published figure for KOOLBLACK is 64% near-infrared reflectance against 3% for a conventional charcoal, which is where the cooler fabric and the lower cooling load come from.
E Screen with KOOLBLACK
Charcoal/Charcoal, Charcoal/Grey, Charcoal/Grey-Stone, Charcoal/Cocoa and Charcoal/Apricot, at 0.5%, 1%, 3%, 5% and 10%, 98 and 122 inches wide. Total solar reflectance runs 28% to 40% across the colourways where the same charcoals in plain E Screen sit between 3% and 10%. Mermet publishes a solar heat gain improvement of up to 24%.
T Screen with KOOLBLACK
Charcoal/White, Charcoal/Grey-White, Charcoal/Grey-Stone, Charcoal/Charcoal-Steel and Charcoal/Charcoal-Iron, at 1% and 3%, 98 and 122 inches. Mermet publishes solar reflectance up to 69% and a solar heat gain improvement of up to 55% for this one; the per-colour sheets show Rs 32 to 40. Every colour has a photograph of its reverse face on the page.
What does not change
Visible light through the weave is 1% to 15% on E Screen KOOLBLACK and 2% to 6% on T Screen KOOLBLACK, so the view and the glare control are what a plain charcoal gives. UV blockage runs about 90% at 10% openness to 99.5% at 0.5%, and the 1% E Screen KOOLBLACK reaches NRC 0.50.
Where a KOOLBLACK charcoal earns its place
West and south-west glass, corner rooms with two hot exposures, and any window where the client wants a dark shade and the room is unusable by three in the afternoon. In South Florida that is most of the top floors on the ocean and most of the Intracoastal-facing living rooms in Fort Lauderdale and Hallandale. We hold 1% for the hardest exposures, 3% where a living room still needs the horizon, and put plain E Screen or T Screen on the shaded elevations in a coordinating colour so the building reads as one specification from outside.
The comparison worth making is not KOOLBLACK against a white screen; it is KOOLBLACK against the plain charcoal you were going to use anyway. Same view, same glare control, same fire listings, a fabric that reflects roughly ten times more of the near-infrared and stays cool enough to stand next to. We bring both swatches to the consultation and hold them against the same window in the afternoon, which settles it faster than any table.
KOOLBLACK on our installations
KOOLBLACK charcoals go on the hot side of our Fort Lauderdale, Miami Beach and Palm Beach jobs, usually alongside a light E Screen on the shaded elevations, on Lutron, Somfy or a manual chain and cut in our own workroom. Our published Mermet projects run light two-tone screens because that is what those clients wanted from the building outside; when the brief is a dark, clear view on hard glass, this is the fabric we specify.
KOOLBLACK: frequently asked
Does a KOOLBLACK shade actually feel cooler?
Mermet publishes a fabric temperature up to 15 degrees cooler than a conventional dark screen, and that is what you notice standing next to it. The mechanism is simple: less solar energy absorbed by the fabric means less heat re-radiated into the room. The published solar heat gain coefficient improves by up to 24% on E Screen and up to 55% on T Screen.
Is the view through KOOLBLACK the same as a plain charcoal?
Yes. KOOLBLACK changes what the yarn does with invisible near-infrared, not what it does with visible light. Visible transmission runs 1% to 15% on E Screen KOOLBLACK and 2% to 6% on T Screen KOOLBLACK, in the same range as the plain charcoals, so the water reads the same way through the weave.
Which openness in a KOOLBLACK?
1% on direct west or south-west glass and in rooms with screens facing the window, 3% in living areas on the water, 5% where a terrace already shades the glass. E Screen KOOLBLACK is also woven at 0.5% and 10% if a window is extreme in either direction. The openness guide covers how we decide.
E Screen KOOLBLACK or T Screen KOOLBLACK?
E Screen for the wider openness range and a charcoal-on-charcoal or charcoal-on-warm-tone face; T Screen for the satin hand, the choice of a white or grey street side, and the higher published reflectance. Both are 98 and 122 inches wide and both go on any roller shade system we install.
Is KOOLBLACK available on a Lutron shade?
Yes, and on Somfy, Crestron, Vertilux or a manual chain. We source the fabric directly from Mermet and make the shades in our Fort Lauderdale workroom, so the fabric choice does not limit the motor choice. Lutron also carries E Screen and T Screen in its own library, which is shown on our Lutron E Screen page.
Mermet koolblack in Fort Lauderdale, Miami, Boca Raton & Palm Beach
Every fabric on this page is sourced directly from Mermet, cut and finished in our Fort Lauderdale workroom on Lutron, Somfy, Crestron or manual hardware, and installed by our own team from Miami to Palm Beach. Our showrooms in Fort Lauderdale (4539 Powerline Rd, by appointment) and Miami Beach (500 South Pointe Dr #150) have motorized shades running so you can judge the fabrics in motion.
Choose the fabric in your own light
Book a complimentary in-home consultation. Shortlist the designs you like and we bring the Mermet sample books, demo motors, and honest answers about openness, colour and exposure.