How to make / buy pure grey paint?

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Does anyone know a method, or where I can buy pure grey paint? Preferably around 12-25% in reflectivity? When I mean pure grey, I am referring to equal amounts of RG&B vlues. Is such a product made off the shelf?

-- Bill Glickman (bglick@pclv.com), January 23, 2002

Answers

Wow, 12% does seem rather dark. Since paint is made out of pigments, it operates on a CMYK mixing system. I am not sure if you can obtain an even set of RGB values.

If you're looking for collour neutral grey, then I'd suggest looking at a Munsell Colour chart and getting a grey which is closest to your needs.

www.creativepro.com has an interesting write-up on painting one's environment a light Munsell 8 grey which can be whipped up at the better paint suppliers. The page also mentioned others who have achieved grey using their own stated formulae. The light Munsell 8 grey is used for the walls and ceiling of the author's workroom that holds his graphic monitors.

-- Erik X (xx@xx.com), January 23, 2002.


Bill,

Find a supplier of Rosco motion picture materials. They make various paints and I seem to recall they do white, black and grey cyc. paint which is colour neutral.

Good luck,

Walter

-- Walter Glover (walterg@netaus.net.au), January 23, 2002.


Erik, I was very intereted in that paint, but could not find that article on the link you provided?

-- Bill Glickman (bglick@pclv.com), January 23, 2002.

Erik,

Thank you for the link - look like interesting reading at morning tea today!

WG

Bill,

I located the article by typing 'paint munsell 8' in the search box. The article is entitled 'The darkroom makes A Comeback Part 2' and in the text is a link to Part 1.

Cheers,

WG

-- Walter Glover (walterg@netaus.net.au), January 23, 2002.


What's your intended use?

It's not really possible to recommend a color space or analysis method without knowing the project if it's technical; if it's NOT technical, then the "match a chip" is probably the best way to go.

-- John O'Connell (boywonderiloveyou@hotmail.com), January 23, 2002.



John, I am using it for grey point calibration for scanning. I want a reference point of something in my image that has equal RGB values. I tried the "match a chip method"....but I am unsure if the outcome is equal amounts of RGB... how can I determine this? I felt there must be some ready made product that is already "certified" grey as one of the posters mentioned above...

-- Bill Glickman (bglick@pclv.com), January 23, 2002.

Bill,

Sinar use the MacBeth Colour-Checker as their reference. It is 'printed' with pigments not dyes.

Walter

-- Walter Glover (walterg@netaus.net.au), January 24, 2002.


Anything resembling paint will most likely change over time because the pigments are somewhat fugitive but not equally so. Even reference charts used to white balance broadcast level television cameras need to be retired from time to time. There is a rather good greyscale chart from Smethurst in England that might serve your purpose, but if you regularly subject it to intense light, it may not last forever either.

-- Robert A. Zeichner (info@razeichner.com), January 24, 2002.

In my experience, reflective/transmissive color measurement devices aren't standardized with grey paint. The last spectrophotometer I used had green and white ceramic reference plaques provided with the instrument.

For technical purposes, mid-tone references aren't as useful as you might think, because humans and machines don't see color space the same way. Your best bet is a Macbeth color reference card (also useful for tests of slide films).

The Macbeth chart would allow you to photograph it and compare the end product (a print?) to it. Otherwise I suggest you find out if your scanner manufacturer has a recommended color calibration scheme.

-- John O'Connell (boywonderiloveyou@hotmail.com), January 24, 2002.


Will you be color balancing the lighting in the room as well? "Neutral" gray is only going to be neutral gray if the ambient lighting is balanced to your monitor as well, assuming you are talking about a room for digital work. Most of the rooms I've been in where this work is done are neutral in tone but have very subdued ambient lighting -- and the monitors are carefully tuned with products like the products from .

-- Ellis Vener Photography (
ellis@ellisvener.com), January 25, 2002.




-- Erik X (xx@xx.com), January 25, 2002.

Geez talk about a misguided answer! I'm sorry Bill, for some weird reason I thought you were wanting to paint the room you were working in, not painting a reference subject. Sorry to waste your time.

-- Ellis Vener Photography (ellis@ellisvener.com), January 25, 2002.

Thats OK Ellis, even you are allowed a mistake once in awhile :-). It sounds like Erik is on the right path... someone seems to have pre made such a paint. It takes the guess work out. I would love to find that source and just buy some. Erik, it looks like you tried to post, but then we got nothing?

-- Bill Glickman (bglick@pclv.com), January 26, 2002.

Err, sorry, Bill, I was just trying to be a wise ass and closing off the HTML tags.

First, www.gretagmacbeth.com has some useful information. Then. I followed its links to one of its re-sellers: www.chromix.com . Gretag Macbeth has a Colour Checker DC for $279, Ouch! Perhaps it is just what you are looking for.

Gretag Macbeth mentions Munsell N 7 as being a neutral grey tone to eliminate colour viewing errors in its light booths. www.creativepro.com mentioned Munsell N 8 as neutral so there is some slight difference there.

I guess your best bet to mix your own patch would be to look for a graphic arts supply shop or production house or a prepress house. The Munsell colour system is the de facto standard used to define colour in the prepress world.

-- Erik X (xx@xx.com), January 26, 2002.


I am sorry. I missed this out. Pantone provides colour swatches with the corresponding Munsell number. If you go to a graphic arts supply house, just ask to borrow the Pantone swatch book. You should be able to find Munsell N 7 or N 8 or whatever value of grey that you need. It may not be as accurate as a gretag macbeth one due to the print quality but it is can come close enough.

-- Erik X (xx@xx.com), January 26, 2002.


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