Help Needed... ww2 Russian Colors

[DLinevitch]

48 minutes ago, Jamie @ Sovereign Hobbies said:

 

The above post contains very interesting sets of colourspace coordinates but they are relatively modern measurements. They are measured using the new 10 degree observer angle standardised in 1964. Previously it would have been 2 degrees.

 

Likewise Illuminant D, whether D50 or the more common D65 as quoted on these catalogue entries was created in 1967.

Of course, the colors of 30-40 circa were not thrown into the trash, they were re-calculated and they are still used. 

 

Edited January 14, 2021 by DLinevitch

[DLinevitch]

11 minutes ago, Kari Lumppio said:

Hello!

 

DLinevitch (Psy06), did these etalons (samples) have numbers?

 

I mean the numbers as listed here (picture below) where one can find also the A(erolak) paints. They were known as A-21, A-22, etc. Later code changed to ПФ-19 and they are available as such even today, see for example: https://www.infrahim.ru/products/1759/.  Note the ПФ-19 means these paints are (were) pentaftal based enamels, not straight oil enamels.

 

https://postlmg.cc/zVd0XRg6  It is my picture taken from Scalemodels.ru thread::  Химия краски “A-“, АМТ и AII? (Paint chemistry “A-“, AMT and AII?)

http://scalemodels.ru/modules/forum/viewtopic.php?t=17492

Actually I had forgotten whole thread as it did not rise much interest there and then.

 

Cheers,

Kari

 

 

Hi Kari :) It is necessary to ask Akanikhin, he worked with this catalog.

[righidan]

Dear friends,

   Sorry for answering so late, but I have had plumbers working in my house all day long, so I have not been able to study your very interesting posts.

   We give color for granted, but when you try to standardize it, it is VERY complicated.

   I believe that to get near the truth we need to use not only standards, but also more than one source of information, among them the study of relics and the reconstruction of the original formulas.

   It is a well known fact that the colors standard of Fs 595 and RAL changed along the years, and we must use the current standards with caution.

   From a thread in Massimo site, with information from Mr. Averin and Mr. Lumppio, the modern notation of the following AMT colors is known: AMT-1 = 924, 935 AMT-4 = 741, 760 AMT-6 = 861 AMT-7 = 952, 953 AMT-11 = 820, 823 AMT-12 = 824, 827 AMT-16 = 842, 843.

   We must note that in the old Russian magazine “War in the air” No. 8 about Il-2 and Il-10, some of these same catalogue numbers are reported.

   The numbers correspond to the color samples in the TU 6-10-1449-(last two numbers of year of issue) produced by VNIITE, the now defunct All-Russian Scientific Research Institute of Technical Aesthetics.

   The color samples in Mr. Linevitch post show these color samples, and the numbers in the page posted by Mr. Lumpio correspond to the same standard, as he has shown in threads on scalemodels.ru and Massimo site.

   A page of the colors still produced in Russia, with numbers, can be found at the address https://lakokraska-ya.ru/ral under the RAL samples.

   Mr. Duff is also right saying that the standard for colors has changed in the years from several points of view.

   As we have data for these colors from the fifties, and we also have conversion formulas from the older data to the newest, we should be able to convert all these colors to the L*a*b* values used these days with the illuminant and the observer degree we use today.

   Unluckily, confirming that Murphy’s law is the fundamental law of the universe, these formulas do not work well for typical camouflage colors.

   I do not want to bore anyone with samples, but using the formulas to change from historical to actual, for a dozen camouflage colors of FS595, only four were reasonably close.

   Mr. Akan has done a commendable job in producing accurate historical colors, but I suppose that he rightly reserves for himself the information that is crucial for his business.

   Maybe the "Lakokraska-Ya" company from Yaroslavl can publish the L*a*b* values for the colors it still produces, and maybe in some archives it still has the formulas for the colors produced during wartime.

   Comparing information from different sources with the spectrophotometric analysis of relic samples, we can reach some reasonable conclusion, and when new data will surface, we can improve our knowledge.

   And if you are afflicting yourself with the doubt, well, yes, I do own a spectrophotometer…

Regards

Daniele

[Massimo Tessitori]

Hi Daniele, 

thank you for your well informed post about color standards.

I have seen some color chips read by spectrofotometers in some web sites and I had the unpleasant surprise to see that some well known colors visualized on the screen didn't resemble much to well known original chips.

For example, the 34102 is notoriously a green, but the chips on the screen based on spectrofotometers showed something between brown and olive drab.

One can think that it was fault of my own screen, but photos and scans of material samples of 34102 (chips, models and real planes) always showed well the green hue, only the chips of these sites appeared off. 

If the screen visualization of greens is unreliable, it's likely the same for all other colors.

So I think that there is some defect in the algorhythm converting the values from spectrofotometers into RGB values for the screen.

Of course, spectrofotometers can always be used to compare two chips taken with different spectrofotometers (I hope) or at least with the same instrument. 

Regards

Massimo

[Jamie @ Sovereign Hobbies]

3 hours ago, Massimo Tessitori said:

Hi Daniele, 

thank you for your well informed post about color standards.

I have seen some color chips read by spectrofotometers in some web sites and I had the unpleasant surprise to see that some well known colors visualized on the screen didn't resemble much to well known original chips.

For example, the 34102 is notoriously a green, but the chips on the screen based on spectrofotometers showed something between brown and olive drab.

One can think that it was fault of my own screen, but photos and scans of material samples of 34102 (chips, models and real planes) always showed well the green hue, only the chips of these sites appeared off. 

If the screen visualization of greens is unreliable, it's likely the same for all other colors.

So I think that there is some defect in the algorhythm converting the values from spectrofotometers into RGB values for the screen.

Of course, spectrofotometers can always be used to compare two chips taken with different spectrofotometers (I hope) or at least with the same instrument. 

Regards

Massimo

 

Hi Massimo, you are correct. The CIELAB colourspace model is quite robust but the RGB model is very limited. To test it, one can take, for example, CIELAB values L10 a0 b-50 - perfectly valid in theory, although in practise you couldn't see such a strong blue as so little light is being reflected. Converting that to which pixels to light up in the RGB model, one can get very weird results on a screen.

 

To others:

To visualise things in practise, my favourite thing to do is take the CIELAB coordinates straight to my NCS1950 fan and look for something similar. NCS1950 is hugely superior to an FS595 fan if you want to do this sort of thing. It has 1950 discreet colours in it, as opposed to FS595's 950 chips in total including many duplicates in different matt, satin or gloss finishes reducing the actual number of discreet colours to look at much smaller than 950.

[DLinevitch]

Modern AII nitroenamel as НЦ-5134 is sold here -> https://www.himtek-yar.ru/catalog/paints/nts_5134/

 

Modern designation AMT/AGT:

AMT-1 -> НЦ-5133 №924, №923 

АМТ-4 -> НЦ-5133 №760, №741

АМТ-7-> НЦ-5133 №952, №953

АМТ-12-> НЦ-5133 № 824, №827

АМТ-16-> НЦ-5133 № 842, №843

 

Sold here -> http://emal-nc-132.ru/emal-nc-5133.html

I asked the manager where to see the color table, he said that the colors can be found ... in the catalog RAL ... [OMG]

 

This is chip actually for AGT-4 enamel (not AMT), and you will laugh, but this is really very similar...  my life won't be the same ...

 

 

Edited January 15, 2021 by DLinevitch

[DLinevitch]

I tried to investigate other color codes, but I came across the fact that for some reason they are not in the RAL online catalog. However, my searches led to such find:

 

AMT/AGT-1 - НЦ-5133 №924, №923 - RAL 924?  

 

 

Edited January 15, 2021 by DLinevitch

[Kari Lumppio]

Hello!

 

Below hopefully my old photo of Revell 87 against the Albom Nakraskok sample:

 

My recollection is that Re 87 is even more close when seen with own eyes in natural lighting.

 

The Revell 87 match was given by couple of IPMS Finland guys like almost thirty years ago. Albom Nakrasok and Soviet colours was theme of one meeting. then Is it really that long ago?

 

Cheers,

Kari

 

PS I try to add here two other comparisons which both have appeared earlier in Britmodeller threads. They are also my photos.

 

 

 

Edited January 15, 2021 by Kari Lumppio

[Andriy Butko]

As an alternative to AKAN you may use HATAKA: https://www.hataka-hobby.com/en_US/c/Aviation-Paint-Sets-Blue-Line/26/1/default/1/f_producer_39/1

[righidan]

Dear Friends,

   Thank you for all the interesting information that is coming out, I think that several lifes will change, and mine for sure

   About what Massimo says, 34102 is an “easy” color.

   It is definitely a green, its official name is “dark green”, if it somehow looks brownish, there is something wrong.

   From the latest 2017 standard, that now is called AMS-STD-595™ REV. A, we have:

ID     Color Group  Specular Gloss CIELAB D65/10   L*        a*          b*              Color Name

34102    Green               Flat                                   38.16    -4.95    12.28            Dark Green

 

In the FED-STD-595C, CHANGE NOTICE 1, July 31, 2008, we had:

Color number Illuminant C  X      Y      Z      60° gloss   Color Family Color Name    Pigment

34102                                 8.41 9.40 6.92                         Green        Dark Green    1, 6, 27, 39

 

It is an abridged table, but it shows the difference in standard used, and also tell us that the pigments used to produce it, are white, blue, yellow and black.

   Now the problem is that when you use official formulas to calculate L*a*b* from x, y, z, what you get is: 36.7433 / -4.5380 / 13.0933 which is close, but the two colors are distinguishable.

   What happens when you use a spectrophotometer?

   We can look at the Picatinny Arsenal Technical Report ARWSE-TR-17001 “SPECTROPHOTOMETER-BASED COLOR MEASUREMENTS” that has measured FS595 samples using a Perkin Elmer Lambda 1050, a laboratory grade instrument that costs like a small car.

   For 34102 what they have measured is: 38.16 / -7.59 / 13.08, and the problem is that these values are more similar to FS34082 than to FS34102!

   Comparing the difference of their measured value with the official ones for 200 colors, chosen for a military use, they got the following result:

   You can clearly see that just one fifth of the measures was perfect (delta up to 1) and that two fifths were visibly wrong (delta from 3 to 9).

   It means that, even if you use a spectrophotometer, a confirmation of your findings trough comparison to a color chip, is a wise thing.

   So what Mr. Duff says is very reasonable, and while FS595 is a good choice for contemporary USA colors, the Scandinavian Natural Colour System is much wider in scope, and probably more suited for a general use.

   Wonderful finding from Mr. Linevitch: the official description of НЦ-5133 is: “Enamel NTs-5133 is used for dyeing fabrics pre-impregnated with NTs-551 varnish, and for painting wooden cladding of aircraft and units.” It sounds like coming directly from the forties!

   The color chips are really impressive, they come from the RAL "Effect" Range Colour Chart, but are not present in the RAL Classic Colour Chart, that costs much less than the “Effect” RAL E1 Box.

   About Mr. Lumppio photos, they show that good research is valid in the years.

   And now, what about scanning an Albom Nakrasok with a spectrophotometer?   It would be appropriate for the 21th century!

Regards

Daniele

[John Thompson]

40 minutes ago, righidan said:

   And now, what about scanning an Albom Nakrasok with a spectrophotometer?   It would be appropriate for the 21th century!

 

That certainly seems to be a good idea, but good luck getting your hands on one - my understanding is that only two copies exist.

 

John

[Jochen Barett]

In addition to any "official" color table (aged, bleached, smudged or like new) I would like to know the tolerances that were acceptable in the day it was used.

 

Like production of an engine bearing, the diameter should be 85,000000000 mm at 20,0000000°C +/- 0,000xy mm ?? and what could be measured at that time and what would have been officially and inofficially tolerated?

 

On top of that I would like to know the tolerances that resulted from paint layer variation and primer. I am somehow unable to accept the to the rest of the world wellknwon fact that every aircraft painter was able to lay down an even layer of 15,0000000000 microns of paint on every part of the plane under any condition experienced in the factory or in the field.

 

I just love this video on Panzergrau https://youtu.be/8swKKyejX0Q 

the first two minutes ar OK as a starter, look at that box on the outside (yes more than 50 years old, time to bleach, yellow and accumulate dirt) and the inside (nice). The rest of the video is valid too, but that box is one sample, painted in one factory with paint from one batch (and a lot of trust in German obsession with precision). Nonetheless there is no reason to use RLM 75 as a substitute for Panzergrau in the first place.

 

But what would have been the tolerances of acceptance for a factory fresh piece of equipment?

 

Would Russia (or any other nation at war) tolerate the variations Humbrol had producing Matt 30 over the years (in a single plant, not counting Chinese productuon as Humbrol)? Or were the trees in Russia full of paint mixers hanged to death with a sign across their chest "I goofed up on mixing paint and sabotageed our war effort!" and where are the gigantic deposits of rejected paint batches?

 

Edited January 19, 2021 by Jochen Barett
typo

[John Thompson]

I don't know about hanged paint mixers, but I do know Russia had colour tolerance limit samples. I don't recall whether these were available during the GPW, or whether they only came into use with the Albom Nakrasok in 1948. Massimo will be able to answer that question, as I'm sure so will Kari and Psy.

 

John

[Werdna]

On 15/01/2021 at 12:26, Andriy Butko said:

As an alternative to AKAN you may use HATAKA: https://www.hataka-hobby.com/en_US/c/Aviation-Paint-Sets-Blue-Line/26/1/default/1/f_producer_39/1

 

Interesting.  Hataka box sets seem to be readily available in the UK, even if the individual bottles aren't.  What is the general consensus on the comparison between Akan and Hataka colours - in particular AMT-11 and AMT-12..??

[John Thompson]

Comparing AMT-11 and AMT-12 from the Hataka Blue set with the same colours from the Akan aqueous acrylic range, Hataka AMT-12 is nearly identical, maybe just a tiny bit lighter than Akan. Hataka AMT-11 is also slightly lighter (more bluish) (anyone watched Yellow Submarine lately? "Are you Bluish? You don't look Bluish...") than Akan, but that's not a bad thing - apparently these colours faded quickly in service.

 

John

[Kari Lumppio]

Hello!

 

In my opinion Jochen raises up the essential modeling question. What was the variation of Soviet colours or official colour of any nation, actually?

 

My answer is: I don't know (try the Derek - Vice Grip Garage tone).

 

Albom Nakrasok IIRC (It's like more than dozen years ) does not talk about colour tolerances. BTW it contained also colour samples for shoe laquers, children's colour pencils, farming equipment paints among others.

 

Akanin has written somewhere (ScaleModels.ru?) that for paint colour checking two bracketing etalons were used. If someone cared to read my earlier posting (last one on page 3 of this thread) there were four colour codes given for green (former A-24) : 741, 742 & 760, 761. I believe these are two sets of bracketing etalon numbers, but I cannot be sure as I do not have the etalons. And as there is two sets it seems at least some variation was allowed. Yes this etalon thing is very much post war, 60's or someting.

 

In the same posting I gave link to the Scalemodels.ru-thread from 2009 where I pointed out the AII paints became НЦ-5134  and АМТ paints became НЦ-5133г, НЦ-5133 relation. Received only two replies! One saying I am wrong and the ABC's reply:"In the 60s in the USSR, paints began to be classified and labeled according to the chemical composition of the film-forming one. Accordingly, the old paints were redesignated according to the new system. AMT and AGT began to be called NTs-5133, AII - NTs-5134, etc. So, here you are completely right." (Google translation, I believe the "ABC" is the author of the AK real colours book Soviet section).

 

My take of this tolerance issue. I use AKAN enamels or the Hubrol/Revell matches I have given here. To complete the set below is comparison of an Il-2 wing piece to Humbrol 65 and 115. It is great shame that Humbrol discontinued their 115 as it is almost dead on! These samples have also appeared earlier here in Britmodeller forum. From the like numbers it seems nobody values Humbrol any more.

 

I cannot believe that Soviets would have discarded any batch of paint on the basis of shade only. The camo greens had pigment composition to camouflage also on the near infrared area (like NATO green ets later in 60's or so) and check with special NIR filter might have resulted a batch to be sent for example used on trainers or so. Others may and surely know more.

 

Cheers,

Kari

 

Il-2 piece and Humbrol 115 (these photos are from July 2007):

 

Il-2 piece and Humbrol 65

 

Edited January 16, 2021 by Kari Lumppio

[dragonlanceHR]

On 1/16/2021 at 7:06 PM, Kari Lumppio said:

The camo greens had pigment composition to camouflage also on the near infrared area (like NATO green ets later in 60's or so) and check with special NIR filter might have resulted a batch to be sent for example used on trainers or so.

 

This is why AII Green was replaced with AMT-4 - it was less visible on the IR spectrum of German aerophoto films.

Both AMT-4 and AII Green are different formulations of the same green colour of the 4BO standard. Previous camouflage colour standard was 3B - that brown OD/khaki shade visible on f.eg. 1940 Soviet helmets. And I-15s sent to Spain.

 

I have pictures of Akanihin holding the colour etalons - a card with two colour samples (low and high allowed value). Mixed paint must be somewhere between or equal to the low or high samples.

I'll post them when I get home.

 

Cheers,

Vedran

Edited January 18, 2021 by dragonlanceHR
Typo

[dragonlanceHR]

And here is the picture.

 

[Massimo Tessitori]

Quote

Previous camouflage colour standard was 3B - that brown OD/khaki shade visible on f.eg. 1940 Soviet helmets. And I-15s sent to Spain.

 

Hi, 

for what I remember, according to the posts related to Akan's work many years ago, there were two different greens for metallic planes: an olive utilized up to 1935-36 and 3B, that was more dark green, around 1936-1938.

Both were based on two oveposed layers of paint of this TB-3

 

This image of two helmets could show  4BO and 3B. Removing the brown traces of rusty metal, it's not too olive.

 

 

This image of a fragment of Spanish I-16 from Isaac Montoya  seems to shows two layers of paint. The upper one could be Soviet AII green, the lower one a more brownish shade utilized before 1937-38. I don't think that it can be identified with 3B.

 

 

Regards

Massimo

[Jamie @ Sovereign Hobbies]

On 1/15/2021 at 9:59 PM, righidan said:

Dear Friends,

   Thank you for all the interesting information that is coming out, I think that several lifes will change, and mine for sure

   About what Massimo says, 34102 is an “easy” color.

   It is definitely a green, its official name is “dark green”, if it somehow looks brownish, there is something wrong.

 

Regards

Daniele

 

Hi Daniele,

 

Not to be argumentative, but I do find human colour perception and categorisation very interesting. In terms of what is a green and what is a brown, the CIELAB numbers quoted, even if they are inconsistent, strongly imply that FS34102 is a yellow with a bit of green in it. I've tried to draw the coordinates in isometric view not so much for you who appears to understand the coordinates but for others less familiar with how this works.

 

To everyone else, it's difficult to draw this in 3D so I have here assumed the a*b* coordinates are fixed as per the first pair in Daniele's post on my x and y axis, but then drawn a column through the z axis intersecting these a*b* coordinates ranging from L value 0 through 100 (i.e. effectively black to white).

 

 

Despite the fact that Daniele along with the vast majority of people would classify most olive shades as a green, objectively speaking they almost always have much stronger yellow components than green components. That's why adding black to yellow zinc chromate results in "interior green", not a green at all since no green pigment was added but an olive shade.

[Massimo Tessitori]

Very interesting. According to these coordinates, the vast majority of the camouflage colors enter in the yellow range. 

[Jamie @ Sovereign Hobbies]

8 minutes ago, Massimo Tessitori said:

Very interesting. According to these coordinates, the vast majority of the camouflage colors enter in the yellow range. 

 

Exactly. A practical example of a camouflage colour displaying a stronger green component than yellow would be something like Luftwaffe RLM70 Schwarzgrün - Merrick & Kiroff's chips giving coordinates approximately L34 a-8.8 b1.07

 

 

... which looks oddly green and somewhat unnatural as a camouflage colour compared to the olives usually chosen.

[Massimo Tessitori]

Maybe this resembles a green darkened by the shadow and made bluish by light diffused by the sky. 

[righidan]

Dear friends,

   Very informative thread!

   Mr Barett has given the address of an interesting video, and his observation about standards is absolutely correct: I have found no instance of any aviation colour being rejected on the ground of its appearance, even if the factories produced colours that looked like the standard, and we cannot use any colour we want.

   I hope that we all agree that AMT4 is not a Granny Smith apple.

   As Russia had a less advanced production system, and less factories, I suppose that its colours had less variations then the U.S.A., but of course it must be proved studying as many samples as possible.

   Maybe Mr. Lumppio does not know the colour tolerances, but he certainly knows a lot about Russian colours, and I am sure that if someone uses his matches to paint models, the results will look correct.

   Finland is a wonderful land, rich with forests, lakes and Russian airplane relics, one of the first places to visit as soon as this epidemic ends.

   Scarce answer from scalemodels.ru does not means that the information given was not true and interesting.

   I made a post with material about the Il-2 “Avenger” and I received no answers at al…

   Vedran shows a photo of Mr. Akan and his three most important weapons: Albom Nakrasok, the etalons of the TU 6-10-1449- and of course Mr. Orlov.

   A very detailed analysis of the colour 4Bo is no more present on Mr. Akan site, but can be found today at the address http://yarosarmies.blogspot.com/2015/04/4_20.html

   It is in Russian, but is easily translated with Google, and it shows the two standards that delimitate the colour 4Bo, explains their use and how close they are, and has RGB and L*a*b* values for these colours.

   Mr Akan described the two colours shown in Massimo post, the lighter  as equivalent to his 83063 Protective (faded) Purpose: V. V. S. R. K. A. and USSR Application: 1925-1930s - full painting of auto / Moto / armored vehicles, as well as painting of the upper and side surfaces of most aircraft.

   The darker hue was described as 83070 3B - Protective, Dark green (faded) Purpose: VV USSR Application: the beginning of the 1930s - 1938 year - full color of the upper and lateral surfaces of aircraft.

   Mr. Duff is, as usual, right: I see Olive Drab as a green, maybe influenced by the fact that it is classified among green colours in the FS595, but it is actually a yellow, as he shows nicely in his diagram.

   From the Wright Field study, we have 22 different formulas for USAAF Olive drab.

   The simplest one is made of Chrome Yellow and Antimony sulfide, a black, plus inert material, but all the formulas are different, and even if they result in an identical colour, you could use any of eleven different pigments, and a few of the formulas did not had a yellow pigment.

   All the colours were classified in the Munsell notation , explained at minute seven of the video shown by Mr. Barett, as yellows.

   The official Color 41 Olive Drab Munsell notation was 5Y 3.2/2, and the colours produced by different manufacturers and analyzed at Wright Field were classified as: 7.5Y 3.7/2; 2.5GY 3.8/2; 7.5Y 3.7/2; 7.5Y 3.5/2 ; 7.5Y 3.3/1.5 ; 7.5Y 3.8/2; 7.5Y 3.3/2 ; 7.5Y 3.5/2 ; 7.5Y 3.5/2 ; 7.5Y 3.3/2 ; 7.5Y 3.5/2 ; 7.5Y 3.6/2 ; 7.5Y 3.5/2 ; 7.5Y 3.8/2 ; 7.5Y 3.5/2 ; 7.5Y 3.5/2 ; 7.5Y 3.8/2 ; 7.5Y 3.5/2 ; 7.5Y 3.9/2 ; 7.5Y 3.9/2 ; 7.5Y 3.2/2 ; 7.5Y 3.5/2.

   So as Mr. Duff said, they are all Yellows, (Y is for yellow) with just one green-yellow.

   I find airplane colour research fascinating: what you see as a green turns out to be a yellow, you have twenty different factories and their chemists turn out twenty different formulas to represent the same colour, you can have a green without green pigments, or a yellow without yellow pigments.

   And then there is the proof that Murphy’s law is the main law of the universe.

   You have just sold your precious soul to the devil, in exchange for a genuine, flawless copy of the original official Color 41 Olive drab, and as soon as you have signed with your blood, you discover that all the USAAF planes were painted with slightly different hues…

   I suppose that Mr. Barett is right talking about tolerances!

Regards

Daniele

[Jochen Barett]

Thank you, and I haven't even opened up this    yet: https://en.wikipedia.org/wiki/Metamerism_(color) (just to through another dead cat onto the table)

 

In the olden days of early color photography the idea of metamerism was put to work on color ballance. An example is seen her: https://www.kameramuseum.de/2belichtung/gossen/trisix-color-finder.html

the Gossen meter has an integrated color finder, one strip of red (of pigment/dye "X") opposed by several strips of red composed by different pigments (abcde composed who knows how), and depending on the light (from candle / tungsten bulbs to blueish daylight) one of these (at a time) would match the long stripe (not working with fluorescent lamps).

 

So in theory it would have been possible to have "one" paint (color code) from two (or more) manufacturers using different pigments and it would be indistinguishable in the sun but would shift on an overcast day or under tungsten light - and in real life car repair paint shops had to fight that problem even after the war.

 

Again: Nothing wrong with searching for "the real stuff" (orders, charts, catalogues, photos, samples, recipes ...), but if Stalin or Hitler (or their representatives) would have tolerated +/- 3% there is no need for us to smash our heads fighting for 0,1% (of new(!) unweathered(!) paint).

 

(still with all my pledge for tolerance I would not measure the pH of paint that has already proven to be seawater proof for 60 years)