OK in the 1960s you could get a two part paint. It used to be called Day
Glo.
The basic stuff was a white undercoat and the colour you wanted on top.
There was a green but most were amber or yellow. I used to paint it on parts
of model aircraft since I was partially sighted and contrast was everything.
I imagine the paint underneath reflected most of the uv so that the top
coat could convert as much as possible into the colour needed.
Brian
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On Tuesday, 27 August 2019 17:25:45 UTC+1, Commander Kinsey wrote:
So why isn't red, yellow, etc as easy to see? If you wear a bright
red tshirt, you aren't as visible as wearing a hi-vis jacket. Does
it convert all the wavelengths into one or something?
Not all, but some. It's fluorescent:
The current standard that sets the requirements for high-visibility clothing
is EN ISO 20471:2013, under the PPE Directive 89/686/EEC. This replaced the
previous standard, EN 471:2003, in 2013. In addition to laying out
requirements on the construction of the garments, CE marked and certified
products must conform to strict requirements on the performance of the
materials, their colour and the degree of reflection from the reflective
strips.
Hi-vis jackets and trousers have no "active" or light-emitting function,
relying instead on an external light source for their luminescence.
- the fluorescent material: this achieves visibility during the brighter
part of the day but also helps to increase visibility at night
https://www.healthandsafetyatwork.co...ble-difference
In a 2009 literature review, nine papers were found that compared the
visibility of fluorescent and non-fluorescent colours. All but one of those
nine trials found that fluorescent colours were more visible to drivers.
Fluorescent clothing in red, yellow and orange - colours that contrast
significantly with the riding environment - was found to be most effective1.
During the day, fluorescent clothing takes ultraviolet (UV) light from the
sun - light we can't see - and converts it into light we can see. The result
is an increase in the total amount of visible light that's reflected off the
clothing, giving fluoro clothing a brighter appearance. This is particularly
the case in low-light conditions, around dawn and dusk.
https://cyclingtips.com/2016/06/does...make-us-safer/
Bright, synthetic and, above all, cheap, the ubiquity of high-visibility
clothing means that it surely symbolises the Britain of 2010s in the same
way that miniskirts summed up the 1960s.
It was invented by an American, Bob Switzer, whose ambitions of becoming a
doctor ended when he was injured in an industrial accident during the 1930s.
While recuperating, he developed a fluorescent paint before fashioning the
first item of high-visibility clothing from his wife's wedding dress.
High-vis first came to the UK in 1964 when it was trialled by railway
maintenance workers in Glasgow.
https://www.bbc.co.uk/news/magazine-14720101
Peter Rhodes, a lecturer in colour at Leeds University, said: "There is
definitely an element of colour blindness. In safety you are trying to stand
out. Conspicuity is the key element, not brightness per se. And if everyone
wears hi-vis, people tend to ignore you."
The biggest market for it now is children. Yoko, a manufacturer and importer
based in Birmingham, says it has made an estimated one million hi-vis vests
for children in the last year alone. Many of these vests are bought by
companies, such as Specsavers and Toyota, which print their logo on the back
and give them to schools, who pass them on to pupils, who in turn become
walking adverts for these companies. Clever.
https://www.telegraph.co.uk/news/hea...ke-lemons.html
Owain