Paint Variances

[mechman]

A topic that's been discussed before is the variance from store to store of their paint mixing machines. One would think that this would be especially true at True Value stores, as they still use the mechanical mixing machines. I've been lucky enough to get samples of what I would consider the 'four main players' in the off the shelf neutral gray paints. I've received samples from cynical2 of both Winter Mist and Winter Mountain. And I should be getting samples from wbassett of Sherwin Williams Gray Screen and others. What I've noticed in measuring samples from different locations so far that there is only a very minor variance between them.



mech

[wbassett]

I agree this latest round of testing has been interesting.

I have always said mixing a neutral is a very difficult task. I never said it was impossible (after all, the professionals mix ) but without equipment to actually check the color balance, and the patience to tweak and retest many many times, doing this by eye is daunting, and dare I say without some luck an impractical way to go about it. Seeing that there are many OTS neutrals and near neutrals already available, it doesn't make sense to mix our way to something that already exists.

This brings us back to the discussion (and often debated topic) of why D65?

Like any color, white comes in more than one shade. In video, white is measured in kelvins, and range from 2,800 (the reddish-orange color of a 60-watt bulb) to 10,000 (the purplish-blue you see in some headlights). The standards committee for analog TV decided the correct shade of white is 6,500 kelvins-- the color of sunlight at noon on a clear day-- and the committee for digital TV carried over the same color temperature as a reference point. More accurately, it specified point D65 along the "black body" curve of the CIE Chromaticity Diagram, and the correct color of white is expressed as points along the X and Y axis of the color spectrum (x= .3127, y= .3290).

Since a video signal is mostly black and white, any deviation from D65-- whether toward the red or blue end of the spectrum-- will bias the picture toward that color. The monitors used for color-correcting TV shows and DVD masters are also calibrated to D65, so your TV needs to be set to that color temperature if you want the images you see to match their sources.

Many have seen me preach D65 relentlessly, some disagree, other's shake their heads wondering what in the world I am talking about. The previous two paragraphs though were not something I came up with, that was a quote from Sound and Vision. I pulled that because it supports what we are trying to say and do here, and it really isn't as difficult as it may seem. Sure mixing our way there will be the long slow road, and for some end with a bridge that is down... but do we really need to mix these grays? I firmly believe the answer to that is no, let the store do it with thier equipment from the list of proven OTS neutrals.

Now the other question comes up is how accurate are the stores and their machines? Some definitely are better than others. Most people buy paint in a store that has many different departments and constantly changing staff. Just because someone is behind the counter doesn't mean they are a paint expert... some are, and some don't really know any more about paints than the customers do. The purpose of a home repair center isn't to provide specialty item service, but rather to cover a very wide variety of materials for people working on projects around the house. Many are not really concerned with exact paint matches, just 'close enough', and there lay the biggest problem with common house paints. It is debatable that craft paints are better, but seeing what they are used for, it is doubtful they are really any better or of a higher quality/QA standards.

Mechanical mixing machines like mech mentioned are fine but can introduce error either on the human side (one click too many or too little) or slop introduced from wear and tear due to age. Also look at the store's mixing station. If it is a mess, it could mean they don't take care of their equipment very well, but that can't be stated as a fact it will cause wild variances.

Lowes uses the Matchrite computer system and Home Depot uses a computer controlled system as well but from my observations they stick to their own colors while Lowes can call up virtually any paint code from just about any manufacturer.

So is close enough good enough? Sure, for most cases people will get a very good screen as long as the gray isn't wildly off, but why take chances with untested custom mixes? Store variances? Well that's going to be a fact of life and yes there will be some slight differences from store to store (and even from can to can from the same store), but from what we are seeing those variances are small.

Here is how professional painters deal with this when they are painting an entire house. They know of this variance and compensate by pouring half of a container of paint into a larger paint bucket, and then half of the paint from another can and then mix that up. When they run out, they repeat the process with the remaining paint. That way they get a consistent shade/color throughout the entire house.

I don't think that is necessary when it comes to screens. A quart is more than enough for most screen applications, and if something happens down the road that necessitates a repair, it's cheap and easy enough to just repaint the entire screen. Before doing that though, test a small area and let the new paint fully dry before making any conclusions as to if the two colors match. Personally, I'd recommend keeping your paint stir stick from the original can and put a dab of the new paint on that for your test. Again, most people will not have any problems where they need to repair just a section of their screen, most would be changing to a different shade or repainting the entire screen area.

So my closing comments are if an OTS has been identified and tested you can feel comfortable that you'll get that color at the store. Maybe this will answer some people's questions as to why some of the commercial screen paints cost so much more than house paints... the answer is much higher quality assurance testing is done by most commercial screen paint manufacturers to ensure each batch meets the same specs, where as home repair centers are not concerned with that level of precision. I have no problem though recommending any of the identified and tested OTS neutral grays.

I didn't mean to go off on a tangent, I just felt this was a related topic and one I have seen some people debate about and get worked up over. Mech has been testing a lot of samples from various manufacturers and although there are some slight variances, they haven't been large enough in most cases to say there was a problem.

I don't think we will be spending much more time with basic grays since there have already been more than enough identified, but this same testing to verify OTS grays is what we are doing to determine color balance in a more advanced mix that does yield a significant increase in performance.

[wbassett]

Mech just PM'd me with something else that probably should be mentioned, and it has been elsewhere on this forum but still is a valid comment that people really need to understand...

That comment is- A person is going to see little to no difference between a gray that is N8.25 and N8.5. Most people will likely will see a difference between an N8 and an N9 and that is where a step gray can come into play, but doing a step gray between that is playing the laws of diminishing gains, and most people will not see a difference between N8.25 and an N8.5, but they may see a difference between N8 and N8.5. Even with commercial screens we don't see this granular of steps for gray screens. Typically it's a light gray, medium gray, and then jumps to dark gray. Again back to D65, some say it's not important, but 50% or more of the commercial screens we've reviewed and tested fall within the D65 'target', and to me that is significant. The better the screen, the closer it is to D65. (Reference the last post and quote from Sound and Vision as to why this is important)

The key really is in the color balance, or more accurately stated, the lack of 'color'. Neutral isn't a color at all, and that can be confusing. What this thread is discussing is variances on paint batches from one company to another, as well as from can to can. Yes, we are saying there will be a variance, but it is a small one unless the store has a problem with their equipment or paint staff. For an OTS (Off The Shelf) gray, the identified grays mentioned throughout this forum will serve anyone well. There really is no need for a list of hundreds of grays that are 'close' when we have many manufacturers supplying D65 grays right off the shelf.

As projectors continue to get better and better, the tolerances of screens will become less important, but the concept of sticking to D65 still remains as far as getting the best and most accurate image reproduction. The closer your screen is to D65, whether it is a commercial screen or DIY screen, the easier it will be to calibrate your projector, and the better the color reproduction will be. Efficiency has also been mentioned, and a D65 screen will also be more efficient at color reproduction, and therefore also be slightly brighter and more vivid than a screen that you have to compensate for at the projector. Keep in mind, any compensation you have to do, be it keystoning, lens shifting, zoom settings, or color adjustments all have an impact on your image. Why mess with a screen that requires compensation? That is our goal and what we are constantly talking about... the best and making it easy as well. Like my signature... things don't need to be complicated at all. Even the 'advanced' screen we are working on and hope to have unveiled next month as a final application is still very easy to do.

How dramatic of a difference are we talking about?

This...


...these...



and this...

It really does look like a 'veil' was lifted from the screen and is even a more dramatic difference in person than anything captured from any screen shoot. (Keep in mind, this is an N7 or darker screen compared with an N8 and N8.5 shade gray screen and it holds its own better than anything I have personally seen be it commercial or DIY)

And what we are talking about is $30 and anyone that can paint a room can paint this screen, no special or complicated methods needed at all, no special rolling methods, no 'hotdog' rollers... just a good quality low nap roller and anyone can do this. How did we get here? By testing and measurements of course. We're currently looking at those tolerances and variances that mech mentioned to determine the best base color and company that ensures a consistent application. Right now, my personal recommendation is if you have a Lowes nearby, check them out and talk to their paint department. They can color match anything within the tolerances we are talking about as well as do perfect matches to any other manufacturer out there, including Behr and Glidden.

[muzz]

I use a nearby Ace Hardware store, that sells Ben Moore Paints.
I prefer to give my $ to the smaller Neighborhood stores like this one, IF the prices are close.
I have plenty of HD's and Lowes around as well.

They can match anyone afaik...
They pulled up the SW Grey Screen NP(via computer), and the nearest they had was BM "Pebble Beach"..

I wish I never used that Behr Poly Topcoat!!