Highflyer wrote:


During WWII they decided to repaint the Spitfire with a flat matt finish
paint so it would be harder to see at night.
It worked, they were harder to see at night. They lost 20mph because of the
increased drag of the matt finish paint.
If you noticed a loss in cruise speed with a slick paint job, I would
suspect your data collection procedures.


You're thinking of Special Night, the extremely matt "anti-searchlight"
black finish specified for night fighters from 1940, and the underside
of bombers from 1939.

Standard camouflage paints at this time had been improved from the
pre-war, biplane era standard by the use of more finely ground pigment
to give a smoother surface. The paints were still matt, but of a sheen
we could call eggshell. These are the "Type S" paints.

Special Night was applied in two stages, an undercoat of smooth Night
and a topcoat of Special Night. In January 1942, de Havilland performed
speed trials with a Mosquito before and after the application of the
Special Night topcoat, and discovered a loss of 26 mph. Special Night
was replaced by "smooth" Night on Mosquito night fighters within a
couple of months.

In August 1942 the Night Fighter scheme was redefined to be Medium Sea
Grey overall with a camouflage pattern of Dark Green on the upper
surfaces. This followed complaints from the squadrons that the night
fighters could be detected as dark shapes on most nights, and that a
lighter colour would be better.

The only single engined night fighters in RAF squadron service during
the "Night" period were Hurricanes and Defiants.