NBR loco paint

[kimballthurlow]

Hello,
I have been "upgrading" a Hornby J83 body to a pre-group livery.
It is clearly not a museum quality work but at least it keeps me off the streets and will give me some satisfaction.
In 2018 I visited the Riverside Museum in Glasgow where I took this photo of a Glen Douglas in probably the paintwork prior to 1923.


I repainted the J83 in my best match for this paint, and I wished to share the following.
It is a bit of a mix, Humbrol tinlet #26 (which has a greenish cast) with a dash of black.
In the raw it never looked correct, but you can see from the gloss patches I have prepared for the decals (Humbrol Clear #35), it is Surprisingly good.


I think the rendering of NBR locomotive colouring has always presented conundrums for artists.
The colour absorption and/or reflection at the brown end of the spectrum seems to be severe one way or another.

Kimball

[Hatfield Shed]

...I think the rendering of NBR locomotive colouring has always presented conundrums for artists.
The colour absorption and/or reflection at the brown end of the spectrum seems to be severe one way or another...

It is difficult for many to accept, but 'colour' is only an artefact of the lighting source, the reflectivity of the object and our visual system. Colour has no 'independent' existence:
Turn the light intensity down and at some point what you see is monochrome, no change to the object, or the spectrum of the light source is required, that's your visual system limitation.
Alter the spectral output of the light source, and perception of colour alters, no change to the object or your visual system required.
Place the object against a different background, and perception of its colour alters, no change to the light source or visual system required.

And the final kicker, even in those with regular trichromatic colour vision, there is natural variation in the peak sensitivity of the eye's colour receptors, which directly influences colour perception. I truly know this because I am a 'divergent trichromat': told during the Physics 'O' level course that 'the Sodium D lines are yellow', when to me they are bright orange, the instruction was to write 'yellow' on the exam paper, should the question arise. 'Yellow' is the majority perception, therefore it is the right answer. (Happily for me, this slight difference means I see things most don't, back in the day when repaired cars with patch paint resprays were common, I could see any in the 500 to 700nm range, no trouble, and this had monetary value...)

(A possibility for Hornby's poor rendition of BR green may be a divergent trichromat having charge of colour matching.)

[Atlantic 3279]

LNER Doncaster loco green looks dramatically different in matt and gloss finishes too.

It is difficult for many to accept, but 'colour' is only an artefact of the lighting source, the reflectivity of the object and our visual system. Colour has no 'independent' existence:

Agreed. I've given up wasting my time trying to tell certain people that there's no such thing as a "correct matching shade" of a colour made from a mixture of ingredients that are not identical to those used in the original example. Variations in perception, and variations in the way that the different components of a pigment mixture are emphasized by lights of different compositions make a "true single match" from non-original ingredients impossible. There's nothing wrong with striving for accuracy of course, but unless the original process and ingredients can be exactly duplicated, the result won't be the same - and as the perceived colour will in any case vary according to observer, lighting, ageing of finish, weathering etc, the pursuit of ultimate accuracy is in some ways futile.
"Anomalous" colour vision certainly seems to have advantages in the right situations too, just as any other anomaly can at times be advantageous. The spotting of camouflaged military hardware in WW2 aerial photographs was, I gather, a task for those with non-standard colour vision, as they learn to look for variations in brightness that give clues to the colours that the rest of us recognize.

[kimballthurlow]

Thank you Hatfield and Graeme for your contribution.
That all makes sense.

Anyway my NBR D class still looks a little brown, but if Hamilton Ellis and others found it difficult ........

I also model German railways, and replication of the rolling stock brown-green of the 1920-40 era is a minefield.
Black mixed with yellow gives olive, whereas blue mixed with yellow gives green.
Imagine the millions of colours available when fiddling with those 3 ingredients. Add red and you have trillions.

Kimball

[exile]

I fear some severe underestimates.

I used to work in the plastics industry and we had to match colours for making items that are fitted inside (and sometimes outside) a car.

We had over 50 versions of black and as many of white. That's before you want a red, brown or grey or whatever colour interior.

Edit to add: and that did not mean having a standard set of ingredients in standard proportions for every material used. The paint would have one formulation, the acrylic fittings would need another, the polypropylene fascia yet another, and the ABD fittings to switches..... Well you get the picture.

[Atlantic 3279]

Well that makes sense, as suspending the colourants in different kinds of plastic is akin to changing the type of oil or varnish in which paint pigments are suspended. Each medium will presumably have its own colour, its own degree of translucency/transparency, and will vary the type of finish between matt, satin or gloss. Maybe other variations occur to due the molecular interactions between the carrier medium and the pigments, changing the wavelengths and amounts of light reflected.

[john coffin]

Having spent a long time modelling racing cars, I am always amazed by the things people forget about matching paint.

The first and most important is to remember that we are dealing with a colour which is either 1/76 or 1/43rd the intensity
of the original. Secondly, we are basically relying on photos which are notoriously inaccurate depending on the emulsion
and the way in which it was processed.

No One any more has any first hand experience of these colours and colouring, and it is well known that each of us sees
colours in a slightly different way.

Two final points, there appears to be a difference between Doncaster and Darlington Green, yet according to LNER colour
specs, the same powder is used for both. However each works used a different primer. People do not really understand
how important primers are to the colour of the top coat. There used to be three types, White, Grey and Oxide. Each as
a base provides a different top coat.

Finally from my days building Ferrari models I know that literally everyday, the "Famous" Ferrari red was a slightly different
colour. The guy in charge of the paint shop mixed up a batch everyweek based on what he felt would be the week's production,
each night he would close the big can that held the paint. In the morning he would re-open it, and add new paint factors to it
generally powder based and quite frequently different amounts each day.

Colour is definitely in the eye of the beholder, and no one is clever enough to be 100 per cent certain that their view is correct.

Paul

[Atlantic 3279]

Agreed again - yet try telling a GER "expert researcher" over on RMweb that even he cannot possibly be old enough, with good enough colour memory, nor have gathered enough information, to state that Hattons' commercial shade of GER teak on their plastic fantasy "Genesis" generic coaches (non-original process, non-original materials, not seen in the same light) is THE shade of inevitably variable original GER teak, and you'll cause a riot if you persist.

[john coffin]

Sadly Graeme, people can't accept facts these days.

I am not sure that I have ever seen the spec for teak on a GER carriage, it would depend on the size they used to flatten
the surface, but more importantly, the type of varnish used and its ability to withstand UVA and UVB rays.

Having spent an awful lot of time up close and personal to a number of preserved ex LNER carriages, I am bemused by
the different shades achieved by the various preservation methods. Even LNERCA cannot guarantee the ability to get each
panel exactly the same. Why do people chose to ignore a couple more important things.
1/ WOOD is natural, and each plank from the same tree can and will have different depths in it which reacts differently
with varnish. I work enough with wood to know unless I stain it, I cannot guarantee with clear varnish that adjacent panels
will come out the same.
2/ Varnish was mixed again on a daily basis, and so would change daily. But also what no one seems to consider is the acidity of
smoke and the atmosphere in steam days which is why it is very difficult in B/W photos to see whether a carriage is painted or
varnished.

Anyone too pedantic is not putting enough sand on their driving wheels!!!!!!!

Paul

[jwealleans]

I have read somewhere (can't recall where now) that the GE and GN specified different subspecies of teak and so GE carriages were yellower than GN ones when initially built. Once in traffic, all the factors enumerated above apply and colours would change over time and with weather and maintenance.

[john coffin]

I am sure that you might be right Jonathan, certainly the GNR specified Moulmin Teak, but I have never seen a
copy or original tender document for the GER, and since they were generally even poorer than the GNR,
they would have used the cheapest they could get.

Teak was in those days generally from What was then Burma, now Myanmar.

There were many teak storage sites in the East End of London after the end of the East India company,
so at that time sourcing would have been easier.

Paul

[Atlantic 3279]

Perfectly reasonable to say that evidence suggests the freshly finished appearance of GER teak is likely to have been yellower than the GNR finish, and to leave it at that. Not what happened on the other side however, and the indignant response to a challenge to an excessive assertion was ridiculous, even if the start of that challenge employed a bit of sarcasm...