One of the few colours made using organic pigments, genuine bone black (burnt animal bones) provides the deepest black possible. We found a version of this paint on the window frames of St Paul's Chapter House, where it was used to black out the windows during German air strikes in WW2.
Blackout looks stunning on the photos of the roof trim along with Whiteley.
Coverage is approximately 15-20m2 per litre per coat (160-220 sq.ft. per 33.8 fl.oz. per coat). This equates to about £6.53 per square metre (US $0.79 * per sq.ft.) for the finished job done in three coats (one coat diluted and two further coats undiluted).
The finished job for Farrow and Ball Exterior Eggshell (plus primer) is approximately £8.92 per m2 and Dulux Weathershield Quick Dry Exterior Satin (plus primer and undercoat) £11.13 per m2.
(* Exchange rate $1.30 to £1.00, December 2020.)