Old style colouring of engineering drawings.

[Maurice Cox 1Participant @mauricecox1]

I have a couple of books with examples of old drawings that have been colour washed, acording to the material used, and whether or not it is in section. They are works of art. I would like to reproduce something of the sort using CAD. I have Henry Adams’ Engineering Handbook, which lists the colours. My question is, does anyone know the RGB equivalent of “Payne’s grey, dark” or “Prusian blue, very pale” and so on. I can get a sort of value for some by scanning the drawings I have, but I’m not sure how well the colours have been printed, and the samples I have only use about four of the colours. A colour chart would be ideal, but I am not too hopeful of one existing. Can anyone help me please?

[Maurice Cox 1Participant @mauricecox1]

[David LittlewoodParticipant @davidlittlewood51847]

Payne’s grey is a dark grey-blue colour, and prussian blue is a very dark blue with a slight tint towards green (as opposed to ultramarine, a very pure blue). The pigment in prussian blue is, IIRC, ferrous hexacyanoferrate (II). If you go into an artists’ materials shop you should be able to find both colours available there in oils, watercolours and acrylics, and it might be worth your while buying a small tube of each in watercolour or acrylic to make yourself a demo card. If the worst comes to the worst you could even give your drawings a wash of real colour!

 

David

[JasonBModerator @jasonb]

Any good art shop should have charts of their “artists watercolours” , not the printed ones but actual hand tinted colour charts though they may not let them be taken out of the shop. The Artists colours use pure pigments although now some are synthetic due to health issues or scarcity of the pigment.

 

Failing that have a look at either Daler Rowney’s or Winsor & Newton’s sites and get the colours from there.

 

You should also take into account that the lighter shades are obtained by using a more dilute mix and allowing the white of the paper to show through so both those colours can actually be quite dark or almost a translucent wash.

 

J

Edited By JasonB on 25/10/2011 20:31:33

[Sub MandrelParticipant @submandrel]

Hooray for such things.

 

I for one think it’s a shame that now computers give us the capability of easily and consistently using colours and textures, maodern drawings look blander than ever.

 

I’m drawing up my little deisel shunter project, and I’m using lots of colour for my own benefit – but I’d never dare submit a coloured drawing to ME*!

 

Neil

 

*As against a 3D model, which it does seem conventional to colour.

[Ed DuffnerParticipant @edduffner79357]

Hi Maurice,

Here are a couple of links to an art website that give you the colours including RGB, CMYK, Web and other values underneath.

http://www.art-paints.com/Paints/Acrylic/Fundamentals/Prussian-Blue/Prussian-Blue.html

http://www.art-paints.com/Paints/Acrylic/Cryla-Daler/Paynes-Grey/Paynes-Grey.html

Regards,
Ed.

[David LittlewoodParticipant @davidlittlewood51847]

Neither of those colour squares look close to the tubes of paint I have here – at least on my monitor (which, to be fair, has not been colour calibrated). The prussian blue lacks the slight turquoise tint I would expect to see, and the payne’s grey does not have the slight blue tint.

 

David

[JasonBModerator @jasonb]

Forget those acrylics, the colours are way off as David says.

 

The drawings would have been watercolour washed so look at the artists water colours as I suggested. The screen colours are still likely to be off but its worth seing what teh RGB figures come out like.

 

Prussian

 

Paynes grey

 

And this is the W&N chat, again screen colours will only be approx

 

 

[Gordon WParticipant @gordonw]

Very interesting. I have actually coloured drawings, in the dim past, tho’ usually for architects drawings. As I recall just used a pan of water colours ( the solid cakes) and washed it on .Modern acrylics look nothing like them, nor do printer inks, tho’ the colour might be true.

[David LittlewoodParticipant @davidlittlewood51847]

Jason,

 

Both those scans are very much closer to the paints I have, and to my memory of other sources. Well done, saved me the trouble of painting a patch and scanning it.

 

IIRC, weak washes of payne’s grey show up the blue tint even more noticeably. Used to use it in the dim and distant past for painting faded blue uniforms.

 

David

[JasonBModerator @jasonb]

Yes they are not bad but best to have a look at the hand tinted colour charts if possible. I know they can be bought but are not cheap. I used to work in an art shop and we always kept them behind the counter.

 

I did do a bit of colour rendering when at college but that was architectural like Gordon. The only painting I do now is with Artists oils and not on canvas but do paint uniforms like these

[Maurice Cox 1Participant @mauricecox1]

Thanks for all the feedback and links. I will try the local art shops for colour charts. When it come to the actual colouring of the drawing, I will probably save it as a jpeg, file, then open and colour it using Photoshop. This will enable me to get much more subtle colour washes than the blunt colour fill of Turbocad. Thanks again.

[Steve GarnettParticipant @stevegarnett62550]

Posted by Maurice on 25/10/2011 19:49:23:

I would like to reproduce something of the sort using CAD. I have Henry Adams’ Engineering Handbook, which lists the colours. My question is, does anyone know the RGB equivalent of “Payne’s grey, dark” or “Prusian blue, very pale” and so on. I can get a sort of value for some by scanning the drawings I have, but I’m not sure how well the colours have been printed, and the samples I have only use about four of the colours. A colour chart would be ideal, but I am not too hopeful of one existing. Can anyone help me please?

 

A quick search reveals the following:

Payne’s Grey – RGB values, etc.

 

Prussian Blue – RGB values, etc.

 

Obviously how well these will reproduce depends entirely on what you reproduce them on. I would have thought that a printer that can be calibrated to do a good job with photographs should be able to manage this okay.

[John McNamaraParticipant @johnmcnamara74883]

Hi Steve

 

Handy site for RGB values

Book marked and thank you

 

Cheers

John

 

 

 

 

[Gordon WParticipant @gordonw]

Why not print out the drawing, on decent paper, then colour using water paint and brush ?

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