How To Make/Buy Pure Grey Paint?

[Bill Glickman]

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

[Erik The Viking]

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.

[Walter Glover]

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

[Bill Glickman]

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

[Walter Glover]

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

[John O'Connell]

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.

[Bill Glickman]

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...

[Walter Glover]

Bill,

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

Walter

[Robert A. Zeichner]

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.

[John O'Connell]

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.

[Ellis Vener]

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 <A HREF = http://www.colorcal.com. ColorVision</A>.

[Erik The Viking]

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[Ellis Vener]

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.

[Bill Glickman]

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?

[Erik The Viking]

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 The Viking]

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.