Recording paint colours

When I worked for a motor factors customers either came in and asked us to mix up Ford Diamond White or whatever .

Pretty sure thats what I used for the invasion stripes on my ’70 Ranchero…:cool::D

Any autopaint supplier will have the tool you need & be able to knock up a batch of paint while you wait…

That’s assuming you have cleaned the sample etc…

When we painted Daytons PRXI we had a book of “standard colours” published by some UK Govt entity which had all the military colours in it. The paint (Centari) ended up on 2 PR’s, the one at Dayton & the one resto’ed at Chino… one was matt & I think the other gloss..but it came out of the same cans…Think we had about 10 gallons of it mixed up.

Looking foward to that!:)

Not this minute, but will be a step closer once the company making my square tube get their finger out…!

…..not a fully restored Whitley then??:diablo:

Not painting anything right now Baz but need to keep a record of paint removed during cleaning… I try to avoid removing paint when possible…

Cheers

Being nosey here, what are you painting?:)

Baz

When I worked for a motor factors customers either came in and asked us to mix up Ford Diamond White or whatever or if they didn’t know the colour name or it was a colour which was non standard for that type of car we got out the colour chips and found the closest match – Simples!
I must admit this was all done working on an as near as possible basis but it worked for what we were doing. I had no idea that colour matching could get this complicated.
If and when I finally get my Rochdale restored it will be Red. The car was originally finished in red gel coat and has since been painted over so luckily no one will be able to accuse me of painting it the wrong non authentic red.

Ok guys – thank you VERY much for all your excellent posts. The subject seems to have been nailed :). I think I’m going to obtain a colorimeter and book of pantones.

NOT the final answer on Colour

Geoff – I am afraid that to my mind your definite position is an approximation.

if you understand the concept of colour space – a 2D space with a and b cords with a 3rd axis of L from black to white creating a 3D space that encompasses all colours- you will comprehend a near infinite number of colours.

Any systems of chips and colour standards (e.g. Pantone) – will only be spots within this space and any match to them – an approximation.

In addition – to measure a colour you need a light source, a sample and an observer. Unless all 3 are standardised – it is an approximation.

In archaeology an approximation may be sufficient. In industry – an approximation is not good enough e.g. car touch up paints…

I cannot see how a set of colour chips can be seen as Hyper accurate – unless observed in an observation cabinet with a defined light source and then defined further with colour offsets – such as 2r 3d (2 shades red and 3 shades dark).

I can see them only as a hyper quick and fit for purpose – within a certain area.

To further impair colour comparisons ;

FYI – did you ever look at the eyes of an old man and see that they are slightly yellow – this is called macular pigmentation and is a process that starts in all humans in mid age onwards. It is a degenerative process and means that you observation of colour starts going yellow compared to when you saw it when younger.

Also 0.5% of females are colour blind. 8% of all males are colour blind.

I am not colour blind – I pass all the standard tests e.g. Ishihara. When tested on a full colour scale – I have a slight green anomaly 4 colours offset in 96 – that means that my colour perception in that area is different to yours – before the effect of age.

Also as there are 3 colour receptors in your eyes – colour blindness means that generally only one of them is on the blink – hence there are several types of colour blindness – dependant upon which receptor is U/S.

Colour matching can be done against chips- but it is a an approximation!

When you scan and get colour coordinates – unless there are a great many chips (several thousand) there will nearly always be a delta E – which can make a huge difference to the most perceptive instrument available – the human eye.

Thanks for the discussion.

THE FINAL ANSWER ON PAINT COLOUR

There are several accepted standard reference sets of paint chips available world wide…..used by archaeologists ,museums etc for transmitting colour information.
To use them is simple…hold sample against matching chip,note chip ref number,send chip ref number to interested party.THIS SYSTEM WAS DEVELOPED TO ENABLE HYPER ACCURATE COLOUR INFORMATION TO BE TRANSMITTED
All this clap trap about faded paint on panels not looking like a picture in a book ,or a downloaded pic on a display screen,is ridiculous.Unless all screens/display devices have been calibrated [and checked frequently] against recognized standards,there is no hope of making valid comparisons.
Elliot wants to investigate and record colour electronically here is a link that will answer those questions….

http://books.google.ca/books?id=tq8QZWNSnVUC&pg=PA232&lpg=PA232&dq=archaeological+reference+paint+colours&source=bl&ots=1-ajd_hVdT&sig=tQkaFFy229bzW62NxswJbqqWy6M&hl=en&ei=GWwmTYX3ONOAnAfr88DcAQ&sa=X&oi=book_result&ct=result&resnum=9&ved=0CE4Q6AEwCA#v=onepage&q&f=false

Guess what??? when you’ve scanned and defined the paint using electronic methods you get a ref number from one of the “standard chip sets” to send to all your mates.

Speaking of color, can you check out that RLM65 over there?

(runs)

There is a company in Leicester that does true colour matching and has set the global standard in true light colour, sadly I can’t remember for the life of me who they are at the moment but I’ll try to find out if you want, they aren’t cheap though.

A bit more info on the DIY shop – they only point you to the nearest standard shade to your reference and from a fairly restricted pallete. A Dulux Trade Centre did a better job for me, they have a bigger pallete and I could check my reference colour against some sample chips and decide whether to take their suggestion or a neighboring colour. No use unless you want to paint your plane with housepaint though unless it comes up as a BS or similar standard colour.

Can anyone suggest any very accurate optical devices that can be used to record colour before stripping? I’m sure a camera is okay, but I’m after something super accurate.

Cheers

i run my own restoration/respray workshop. working with all types of vehicles and aircraft. restorebike.com. ive also produced some ww2 airframe parts for my own enjoyment into seeing how hard it is to produce a hard to get hold of item, such as a HE111 tail swastika..
ref the chromemeter thingy. if you pop round to the local car paint supplier they should have one of those gizmos. although a word of caution, as stated by previously the paint will have lost some of its true colour over the years, also its very true that colours at the time of manufacture were made “as close as”. on some stations where local repairs were made the replaced parts would also have been painted on site and not always to factory spec. during the building of a new aircraft many of the components were farmed out to smaller factorys to avoid mass destruction during a german bombing raid, so again each factory had its paint shop mixing paint “as close as”.
as a solution to try and gain the correct colour. carefully clean an area of airframe that has a good solid bit of paint, then apply a thin coat of satin varnish to bring back its true colour. try to avoid a heavy solvent based varnish as this may react with the paint, some if not most airframes of the time had a satin sheen to them.
other than that try contacting the resto centres at Cosford or Duxford and pick thier brains but im sure you may have already tried that?

Just a thought – but the paint matching machine at your local DIY shop – where they offer to match a paint to your sweater etc.. They use the same hand held kit.

I just don’t know whether they will give you an Lab data set or just a recipe for their paints

FarlamAirframes, great post, very informative.

thanks
Baz

Being nosey here, what are you painting?:)

Baz

just a thought

the colour you are recording may be the result of years of weathering, contamination or exposure to UV light – rather than the original colour.

The other thing is that there was some variation in different batches of paint purportedly mixed to match an official specification.

So at the end of the day – unless you find an unopened can of original paint, about right is probably as good as you could get – and nobody would be able to challenge you anyway!

or check with a model maker…………..

Some Spitfire and Swordfish interior colours come to mind – nothing at all like the good auld Aircraft grey-green we all know and love.

Andy my monitor is not for travelling!

Elliot to colour measure you need a colour measuring device – a colorimeter.

When I studied colour science at Uni – there were bench top and hand held devices.

Manufacturers were Hunterlab , Macbeth and Minolta

Hunterlab are still around as are Minolta

http://www.konicaminolta.eu/measuring-instruments/products/colour-measurement/chroma-meters/cr-400-410/introduction.html?gclid=CMns-L2hpqYCFY9O4QodWj79Xw

http://www.hunterlab.com/

I always liked the hand held Minolta.

Essentially you need a device that will give you a measurement in colorspace – L.a.b. with chroma and hue. This is the unique colour coordinates in the 1976 CIE Lab colour space.

http://en.wikipedia.org/wiki/Lab_color_space

Now you have a colour – how do you match it.

When comparing any approximate colour you test against the same value and get a Delta E ( Emphladung ?) as the difference in colour between two points. Unfortunately if I recall colour space is non Euclidean – If I recall a general rule was a delta E of 1 or 2 was close enough that you would not see it.

If you are trying to colour match against a sample from a 60 year old paint – then you will get the colour coordinates for the aged paint – as Andy knows from his Sky paint discussions – when you age something – the colour changes.

So to match a modern colour formulation- you have to make test samples and age them in a Xenon Arc to evaluate how the compare.

Unless of course it was just for the short term- so match against the aged sample and cross your fingers it doesnt move…

A final point is that you have to assess the light source – D65 is the normal. But if you view under different lights – e.g. Tungsten, Cool White Fluorescent, TL84 etc – the colour you see may be different – this is called metamerism.

If you don’t have a colorimeter in you cupboard – you can either –

1. Get a test flake of paint and use a UV/Vis spectrophotomer with a reflectance chamber inside.
2. Got to a University with a colour lab and test it there.
3. Find a paint manufacturer ( International/Dulux/Crown) and blag them to test them.

Apologies for the detail – it was my Degree and PhD speciality.

Just one note of caution – the Pantone method would be good for recording / noting a colour, but it could be a nightmare for then trying to match an industrial paint to it at a later date! (Bitter past experiences between the marketing people and production!! :eek:)