By C.M.Wilson
PREFACE
Color mismatches often perplex even the most seasoned painter. However, most mismatches are predictable and avoidable once we have an understanding of the science of color and the underlying reasons that mismatches occur.
Each Paint Manufacturer has their own tools and resources that we can utilize in our effort to choose a formula and match a color. While the strategies and techniques outlined here can be utilized by any painter of any skill level with any paint line and result in profitable gains, there is a presumption that the reader has as at a minimum, basic automotive refinishing knowledge and skill.
It is curious to note, however, how difficult it is to introduce new habits, particularly to The Skilled. It’s no mystery that people as a whole resist change. “Better the devil you know rather than the devil you don’t” or “We’ve always done it this way”. However, if the outcome of the change was predictable and favorable, would you still resist? Would you say “NO” to the change of an additional $100 a week in your pocket? That’s precisely what many painters do by continuing down a previously traveled road that predictably leads to delays and obstacles.
Of all the tools and resources in the paint shop, the most important by far, is The Painter. What makes The Painter so valuable is the ability to adapt. To learn and implement new habits, skills, ideas, etc. This is periodically going on, often serendipitously, but the intentional implementation of predetermined habits, skills and ideas is not.
Pre-Meditated Success I say.
TABLE of CONTENTS
I- Dimensions of Color
II- Variables Affecting Color
A-Sunlight vs. Artificial Light
B- The Human Eye
C- Existing Coatings
D- The Painter’s Contribution
III- Habits of Efficiency
IV- Color Library
V- Advanced Tinting Techniques
A- Adjusting Value
B- Adjusting Hue
C- Adjusting Chroma
D- Be Creative
VI- Invisible Repair
A-Philosophy
B- Cleaning
C- Inspecting
D- Sanding
E- Priming
F- Block Sanding
G- Masking
H- Application
I- Blending
J- Nib Sanding & Polishing
K-Time Management
DIMENSIONS of COLOR
There are books and classes and reams of material surrounding color. Plotting and analyzing, descriptions of movement, color theory and academic exercises that don’t always have a clear practical path of application to the production environment. For our purposes here, we will simply address the basic dimensions of color, emphasizing the fundamentals. So let’s review.
It is important to properly describe color, the three dimensions are; value, hue and chroma. Value is how dark or light it is. Hue is red, blue, yellow, etc. And chroma
(or saturation) is how rich and pure, or muddy and washed out a color appears. It may help to think of these three dimensions like adjustments on a television set. Value is the brightness knob. Hue is your tint knob. Lastly, chroma is your color knob. A good exercise is to play with your t.v. and see how each dimension affects perceived color.
VARIABLES AFFECTING COLOR
Sunlight vs. Artificial light
How we see color is largely affected by the light source. Sunlight is the standard we measure with. The true white light spectrum that the sun presents, gives us our most accurate color rendering. This light contains all the colors of the spectrum, which are red, orange, yellow, green, blue and violet. A prism will refract the white light into a visible color spectrum, much the way raindrops in the sky will, and allow us to see a rainbow. There are 3 primary colors, (red, yellow and blue), and three secondary colors, (orange, green and violet, which are a mix of two of the primary colors). This represents the fundamental color wheel. Further mixing of neighboring colors gives us a seemingly infinite choice of hues. All colors are bound by the color wheel and can only be off in one of two directions, with the exceptions of black, white and silver. These three can be off in any direction, but are still bound to the wheel once the predominate hue is determined.
Primary colors. All colors originate with these three.
Primary and Secondary colors. Hues are bound to the wheel in the fact that they can only shift around the wheel to neighboring colors. You cannot go across the wheel.
For our purposes in the paint shop, we use a modified color wheel known as the BRYG wheel. It contains blue, red, yellow and green.
When light strikes and illuminates an object, the color spectrum is absorbed into the object, except that which is reflected back, giving us the color we see. For example, only the yellow portion of the spectrum is reflected back from the banana, so we see the banana as yellow. Now if we change the spectrum to a narrower wave length, (such as shoplights), then there are less components to reflect back. Therefore, a different light source will typically make things look different, or mismatched. This is called matamerism. The distinction is important to us, because our paint job isn’t going to be examined under shop lights, but sunlight. So we must analyze and match color with the proper light source, as light source is a potential cause of a mismatch. Also important to note, there are probably more “redo’s” due to transparency than slight hue differences. So adequate illumination, a bright enough light to reveal coverage (or lack of it) as well as how the metallic is behaving, is a very helpful tool. A particular light related challenge is manifest in some yellows that contain certain organic pigment compounds which are photochromic, that is, exposure to the sun can visually shift the color. We don’t see this with synthetic pigments.
The Human Eye
The human element is a variable that exists regardless of the light source. Factors include age, ethnicity and gender, as the rods and cones of our eyes are different and can render perceived color differently. Injury can also affect our ability to see color.
A “color eye” can be developed as well, through practice and experience, and oft times a manager or bodyman may have a well developed eye. A wise painter will utilize the resource of other eyes whenever necessary, there is no shame in this. Practice analyzing mismatches that you see on cars outside of work. Repetition is the Mother of Skill, and the only substitution for experience, is Divine Intervention.
Existing Coating Variables
Additional mismatches come from the vehicle manufacturer. Transparent coatings, different finishing and assembly plants, different “lots” of paint, and of course, plastic verses steel can all contribute to challenges that must be dealt with.
Age of the vehicle and ultraviolet exposure also affect the paint, even creating mismatches between panels of the same vehicle. Such as the hood fading more than the fenders as a result of more intense exposure from the sun. It’s important to analyze a color relevant to the area you will be refinishing. Don’t match the hood to paint a door.
Furthermore, perhaps the vehicle has already been refinished in the field improperly. Or
with the wrong color formula. Or not enough color to cover, blah-blah-blah, we’ve all seen it…, Paint work we’d be ashamed to say was ours.
The Painter’s Contribution
Many a painter has caused his own problems as well. Inadequate agitation of the toner bank, or incomplete mixing of the color. Haphazard application of color. These all produce unpredictable results.
In summary, all these variables add up to one conclusion: Nothing ever always matches.
Therefore, this variety of inconsistencies demand we should generally be blending to ensure a color match that will fool the eye.
Traditionally and historically, we’ve been taught to tint as a last resort. We’ve been instructed to alter the viscosity of the paint through more or less reduction. Or alter the speed with different reducers. Or make gun and technique adjustments to lighten or darken a color.
I suggest to you, that those techniques introduce yet more inconsistencies. If we are consistent, we are predictable. If we’re consistent, we’re able to reproduce results that have succeeded in the past. In other words, we can plot a known course for success, rather than swerving to avoid failure.
HABITS OF EFFICIENCY
There are a few changes you may need to make, but the changes will not take more time. They are simply different habits. Habits which will result in saving you time, and strategies that will make you more profitable through increased efficiency and accuracy.
Don’t be the painter who scrambles to “fix problems”, problems you yourself helped create through inconsistencies. We eventually learn that one can never paint anything fast enough a second time to make money. Let me say that again, You can never paint anything fast enough a second time to be profitable, to either you or the shop.
First off, you need to be consistent in your application of color. The appearance of the color can be altered through inconsistencies. So be consistent. Consistency allows you to paint cars apart, even silvers and pearls, and have them match once they’re put together.
Second habit to get into, is always making a spray out card of the color you’re spraying. If you do this, and this alone by itself, it will cost you time. So make your card when you are either jambing the parts, or at the actual time you are painting the car, so no extra labor or time is involved. These cards are clear coated and saved. Regardless of whether or not you have a card of the current color you’re spraying, you should be spraying a card every time you paint a car. The reasons are to ensure proper coverage and so you can double check the color in the advent that the formula has changed.
There is no reason to let your efforts in creating these cards, be limited to benefiting that one particular job. The more you use these cards, the more time you save deciding on which formula to mix as you eliminate the need to ‘reinvent the wheel‘ each time. So third habit is to file the cards according to vehicle manufacturer, with code and/or tint notes on back, for future reference. Your system of filing must be convenient for you. If it’s a burden to retrieve cards and takes too long, then the benefit of saving cards is negated and you won’t use this resource effectively, if at all.
THE COLOR LIBRARY
In short order, you will have built your own color library that is a true representation of your unique and consistent techniques. The first time you come across a “new” color for which you have no card, resist the urge to “match it on a stick” before you spray it, it may appear different once sprayed and cleared, (and this is even more pronounced with water-borne colors, so best to develop that habit now). Besides, it may match well enough to blend, right out of the can. Additionally and most importantly, you want an untinted spray out card for future reference. If you need to tint the color, make a new card and write your adjustments on the back. Now you have a “standard” as well as a “corrected” sample for future use.
When analyzing a color card, with proper lighting, at the relative angles, it’s important to compare the car to the card. Consider a blue car. Because blue is bound to the color wheel, it can only be too red or too green, hue-wise. So we say, “The car is redder than the card”. This by default, tells us which direction to move the paint, we must tint the paint redder. Likewise, if you are comparing a previously sprayed card (from your color library), and you can see that the car is too red, ( or the card is too green), then you can with-hold a portion of the toner that is creating the green. I call this with-holding of a toner “reverse tinting”. Again, accurate documentation on the back of your card allows repeatability in the future.
Now, which dimension of color do we adjust first? Whatever is most noticeable. We’re not going to tint to match, but rather tint to blend. Many times, fixing the most obvious problem will result in a blendable color. However, some discrepancies can not be blended out, such as a dark flop of metallic. That must be lightened, or the offending metallic identified, and a formula variation that isn’t using that metallic is used. This is a case where ‘old school’ tactics probably won’t work. The advice to over reduce, use a faster reducer or dry spray the color to lighten it, just isn’t a sound strategy these days since we’re not dealing with simple metallic. Today’s “metallic” isn’t always metallic. It may be mica, or titanium dioxide, or spherical aluminum but regardless, it doesn’t always behave like “good ol’ metallic”. Again, be consistent so the results can be predictable.
In addition to your color library by vehicle manufacturer, you’ll also want to have a file of the metallic toner spray outs. These can be utilized to identify proper size and characteristics of the metallic. The benefit here is to be able to avoid a particular metallic that may be giving you a dark flop that you’re fighting. Unlike your color library that may grow each time you paint a car, your Metallic Toner file will cost you 30 minutes initially to spray out, but will then be at your disposal.
Also, a black spray out file, of the toner bank blacks, as well as any blacks you actually mix and spray. You might be surprised how many times Ford’s UA matches VW’s L041, resulting in only a handful of black spray out cards to cover most black cars.
The more you use your color library, the easier the habit gets. The easier the habit gets, the more efficient you become with this resource, and, efficiency makes everyone more profitable.
ADVANCED TINTING TECHNIQUES
Now, let’s examine a tinting technique that’s like using a flashlight, it clearly reveals the direction you’re going. You may be familiar with “finger painting”, putting a drop of a toner on a paint stick wet with your mix, and smearing it together with your gloved finger, so you can see the direction it will take the paint. When you’re satisfied with your choice of toner, you dribble some into your mix. Sometimes this is effective, other times it leads to, “too green…too red….too light…too dark…TWO quarts!”
Controlled Tinting
I recommend a couple of habits here. First and foremost, you know you need to tint because you’ve already sprayed out a card for your library…right?
OK, pour off some of your mix into a different container and set it aside. Now we’re only adjusting a portion of the mix, so if we go “too far”, we can easily “bring it back” with some of the original mix. Second, using a small mixing cup (I’ve used paper coffee cups for years), pour off a tad more. This small cup is what you will dribble toner into and tint. Over-tint it so you can clearly see the exaggerated direction its going. This over-tinted sample is now your “tinting mix”. Dribble some of this into your previously poured-off container of paint. Spray the card and check it to the car. Only the card. If you’re “tinting while you paint”, you must avoid piling coat after coat after coat of the wrong color on the car. Finish the car off once you’ve achieved a blendable match.
As we analyze our color, it may help to break it down to the simplest terms. Let’s consider blue. It can only be:
Too light or too dark
Too green or too red
Too muddy or too rich
And if it’s a metallic, Too coarse or too fine.
While it may be off in more than one dimension, it’s typically best to pursue one direction of correction at a time. Start with the most obvious or offensive dimension. Oft times, that alone will get you blendable.
Adjusting Value
As vehicle manufacturers continue to apply thinner and thinner film-builds of color, and heavy metals are eliminated from paint lines, we see undercoats playing a greater role in the top coat due to transparency. As you recall regarding color, we see what’s reflected back. Therefore, the undercoat becomes either a help or a hindrance, depending on whether or not we’ve managed to match the value of the undercoat to the value of the color. Black and white television is perhaps the greatest teacher of color value, for it renders color in shades of grey, from black to white. Ever see blood in a black and white photo? Pretty dark. Other reds are a light grey. If you match the value of the color, you’ll achieve coverage in fewer coats of paint. That saves you time, and the shop material, (read increased profitability for both).
One way you can practice your value evaluations, is to look at black and white photos of known items. What shade of grey is the sky? Your house? Your car? This is simply another exercise to help you develop your color eye.
Nonetheless, there will be colors encountered that are either too light or dark in spite of the correct value undercoat and full coverage. That being said, black and white are perhaps your worst choices for altering the value of a color, as they both severely affect the dimension of Chroma. Now is the time to refer to the formula and utilize the dark or light tints within that color to increase or decrease value.
If it’s a metallic color, then you must also address any dark or light flop issues. Most Paint Lines have some sort of a flop adjuster that essentially re-orientates the metallic so it reflects more. However, there is a limit to how much you can use. If you find you need to use more than is recommended by your Paint Line, then its time to get out your metallic spray cards and find a formula that utilizes a non offending metallic.
Adjusting Hue
The following chart illustrates how hue behaves.
COLOR ADD TO CHANGE A CAST OF
Blue Green Red
Blue Red Green
Green Yellow Blue
Green Blue Yellow
Red Yellow Blue
Red Blue Yellow
Violet Yellow Blue
Violet Blue Yellow
Orange Red Yellow
Orange Yellow Red
Yellow Green Red
Yellow Red Green
Remember that Whites, Blacks and Silvers can be off in any direction but once you have
determined the predominate hue, you can move it accordingly.
COLOR ADD TO CHANGE A CAST OF
W, B & S Green Red
W, B, & S Red Green
W, B & S Blue Yellow
W, B & S Yellow Blue
Adjusting Chroma
It’s fairly easy to de-saturate a color, because black and white will both muddy it up. One darker, one lighter. On the other hand, it’s difficult to come back from a color that is muddy or washed out. This is a prime example of why you want to utilize the Controlled Tinting tactics discussed earlier, it allows you to “creep up” on the color movement. Furthermore, the toner chart from the Paint Line you’re using is the go-to tool here. On that chart, the toner characteristics are noted as well as the toner position on a color wheel and the relative chroma of each toner. The ‘cleaner’ or more chromatic colors are on the edge of the wheel. The ‘dirtier’ or less chromatic colors are towards the center. Using the formula to identify the toners in the color, use the ‘clean’ or ‘dirty’ toners as determined by the toner chart, to adjust the chroma. However, bear in mind that you can not adjust the chroma without affecting the other two dimensions, so go slow! Controlled tinting!
BE CREATIVE
Most any formal tinting class will dictate that you stay within the formula when tinting. This is indeed good advice, when it’s possible. Sometimes it’s not. If we only ever dealt with a factory paint job that may have slight variances, then it would be more probable. But due to the vast variables affecting color, including mopping up after someone else’s repair, we must at times think outside the box. For example, it isn’t uncommon to find a formula that simply won’t go where you need it to go, regardless of what you put in it. Sometimes the answer is to withhold something. Remember reverse tinting techniques. Other times, you must look outside the formula and apply color dimension fundamentals in order to get the color to behave as you want it to.
INVISIBLE REPAIR
We all know how important color match is to an invisible repair as it’s often the easiest to see. While it is easier to see, it by no means is the most important factor. The Invisible Repair is a sum total of many components. Each step of the process’ success is connected to the prior step.
Unfortunately, the repair field has been inundated with less than qualified technicians. From the ’student’ who won’t implement procedures due to ‘time constraints‘, to the ’genius’ who has discovered ‘tricks unbeknownst’ to the R&D Chemists who developed the paint lines, to the guy who just doesn’t care–fundamentals are ignored at an alarming rate.
Of course there is latitude in the approach, for example, some painters wash a car prior to starting the prep process, some painters clean only the repair panels. That’s not the same as ‘some painters clean the panel, some painters don’t.’ The panel gets cleaned either way. If this fundamental step is skipped, there are consequences, namely, the potential for surface contamination is greater, and therefore, the repair process has the potential to be slowed down as the surface contamination is dealt with later and out of The Logical Sequence.
PHILOSOPHY
It may be important to discuss the Philosophy of Invisible Repair before we analyze the fundamentals. The desire for the Invisible Repair must start at the top, for employees typically follow the lead of the owner/manager. While a sense of urgency is without a doubt a valuable work ethic, ‘crazy-scrambling-inaccurate-rushing around’ is not. An atmosphere that promotes a smooth, accurate work flow is invaluable. It’s not a matter of taking longer with the process, but rather a different process that takes no longer. We’re simply talking about different habits that are conducive to efficiency and productivity. A key component is a clearly communicated level of quality expectation, including weld grinding/finishing or factory seam sealer replication, etc. These can be tell-tale signs of a repair which can not be addressed in the paint shop. Simply put, to ensure an efficient flow, all techs need to be on the same page regarding the Invisible Repair, and this must manifest from the top down. An attention to detail from the technicians is required. Not just performing a process for the sake of going through the motions, but an honest, ‘in the moment’ approach to see a procedure completed properly. Focus on the task at hand.
CLEANING OEM & PREVIOUSLY PAINTED PANELS:
As earlier noted, improper surface cleaning can lead to contamination. Contamination can lead to prolonged repair time at best, or product failure at worst. The Logical Sequence dictates that our first operation is cleaning the panel. Start with waterborne cleaner or soap & water. This takes care of most organic contaminates. Continue cleaning with a solvent borne cleaner. This takes care of most petroleum contaminates. On some jobs, it may be necessary to clean using an old grey scuff pad with a water/solvent cleaner and scrub the same way you would wash dishes, rinsing well.
INSPECTING A REPAIRED AREA:
The repair can not be inspected properly without 1), adequate lighting and 2), the repair area must be blown off & free from sanding dust. The sanding dust can hide scratches too deep to prime, as well as pinholes. A word regarding illumination: the best lighting is generally in the booth, which is one of the worst places to find a problem. Therefore, use an auxiliary light source during your inspection process. Shine the light across the panel, parallel to the surface and it will cause scratches and pinholes to cast a shadow, making them easier to see and address. Additionally, now is the time to feel the work and be certain it’s straight enough for priming. If the work isn’t straight, or there are pinholes, scratches or grinder marks, then its not ready for priming. If you ignore those problems and prime it anyway, it will likely result in needing to be re-primed later. Re-priming doubles the material cost of this operation and adds to the cycle time. A repair that has excessive pinholes, grinder marks or isn’t straight should be sent back to the bodyman. Minor pinholes and scratches can be addressed in the paint shop.
Primer-filler or surfacer, has limitations. Asking it to do too much is guaranteeing a failure. Deep scratches and gouges when primed over, will behave like expansion joints over time and be revealed as they telegraph to the surface.
SANDING A REPAIRED AREA:
After blowing off and inspecting the repair, and ascertaining its readiness for the paint shop, we’re ready to sand the paint edge. Starting with 220 or 240 grit paper on your DA, feather the edge, about an inch per layer. Graduate to 320 or 400 grit and sand a few inches past the 220/240 sand scratches. Blow off and clean with a waterborne cleaner and blow it off again. This ensures you’ll not be priming over sanding dust and allows you another chance to inspect the surface. It may be helpful to keep in mind, that the transition of the surface to be primed needs to be gradual. An abrupt change in the surface will almost always make its way to the surface, resulting in what we know as shrinkage or sand scratch swelling. The primer performs best when it has a smooth bed to lay in.
How much time can be saved in the future if you don’t have to re-prime a job. Or polish or repaint a previously refinished vehicle that has come back due to shrinkage?
The unqualified painter will most always blame the product, rather than the process. Shrinkage is so common, that the myth that primer must dry overnight to be cured and ready for sanding has been born. Ignorance and apathy have further nursed this myth.
PRIMING THE REPAIR
Each Paint Manufacturer will have their own specific guidelines regarding primer/surfacer application. Generally though, three wet coats with proper flash time between coats is recommended. Ignoring flash time seems to be a common offense. As a result, piling on coat after coat results in poor build and shrinkage. To attempt to shave time off the process by omitting the flash time, actually adds time to the Invisible Repair.
BLOCKSANDING THE PRIMER
Using a guidecoat and sanding blocks to ensure a straight foundation is a fundamental skill all painters must master. Here I recommend a couple of tips. First, use a powdered guide coat. This not only completely covers the area to be sanded, but is also re-applied after block-sanding to reveal those scratches and enables you to eliminate them as well. This re-application is necessary because you should start your blocking with 240, graduate to 320 or 400, all the while, leaving enough material to allow you to finally finish it off in either 600 orbital with an innerface pad, or 800 straightline. Remember, an orbital scratch is always less aggresive than a straightline scratch of the same grit. Additionally, we’re after an Invisible Repair, so don’t leave scratches that must be bridged over, in an attempt to be faster. You’ll spend more time on it later after it shrinks. Blend areas are sanded with either 1000 wet by hand, or 800 with an innerface pad on the DA after cleaning. With either procedure, pay attention to edges, as sand-thru’s are common to the wandering mind.
MASKING
Detrimming components rather than masking them has become the norm. It certainly makes for an easier prep for the painter, but there are times when masking is still necessary. Its important to note, that along with “precision mask”, “precision prep and cleaning” are required to ensure the success of the repair. Another efficiency killer and dead giveaway is overspray. It always takes longer to clean it later than to prevent it in the first place.
APPLICATION OF COLOR AND CLEAR
While there is no way to adequately cover all Manufacture’s recommended application procedures, there are some common guidelines that can generally be applied to all lines of paint. Presumably, you’ve properly prepared and cleaned the surface and are utilizing a ground coat or sealer that matches the color’s value. As you apply your color, observe flash times! This will actually allow the color to cover faster. Use an auxiliary light to ensure coverage and metallic orientation, prior to clear coating. And generally, apply your first coat of clear the way you want your last coat to look, so be mindful of the texture you’re trying to match.
BLENDING
It is a subjective call as to whether nor not you can stay on the panel or if you must blend the adjacent panel. Condition of the car, amount of room left to blend, the color and color match skill of the painter all factor in. A fair and honest assessment is required. A general rule of thumb is if you’re left with less than 1/3 of the panel, then blend the adjacent panel. Of course, if you’ve been faithful in building your color library, you may well be able to determine that six inches is “plenty of room with this color”. But, it is often a quicker path to an Invisible Repair to simply blend the adjacent panel. Furthermore, taking advantage of style lines, mirrors and door handles to help hide a blend is a good strategy. Another tactic to employ when there are no such features to help hide a blend is what I call “Geometric Blending”. This is where you blend, from the fender to the door for example, and rather than a straight top to bottom blend, you allow the blend to progress further and further across the door the lower you get. This creates a diagonal blend, which is easier to fool the eye than a straight blend.
NIB SANDING AND POLISHING
You may find it necessary to either nib-sand some imperfections, adjust the texture, or both. Here is another area where Logical Sequence promotes efficiency. First, if possible, leave the vehicle masked. This allows an easier cleanup. Second, get rid of the imperfections with a nib-file or blade scraper. If you attempt to sand it out with too fine a grit, you leave the ‘ghost’ of the dirt nib. Too coarse a grit and you may remove too much material. Next, gently sand the area with a grit you can buff out. I prefer a 2000 grit 3” disc on a baby-DA. If you need to address the texture, now is the time prior to buffing. I prefer 3000 grit on an innerface pad. Buff and polish as normal. Again, utilize adequate lighting prior to unmasking to ensure no ‘under buffs’ have been left behind. If you’re not sure, run the buffer over it again, this is demonstrably faster than doing it later, after the car has been unmasked and detailed.
TIME MANAGEMENT
In order to successfully pull off the Invisible Repair in a production environment, we absolutely must control how we spend our energy and efforts. Most every procedure in the paint shop can overlap with another. However, you must use common sense when pairing procedures. You’re not going to sand on another car while you’re waiting for clear coat flash time, but you could apply a coat of primer during that same flash time. Yet, without the forethought to have previously prepared the repair for priming, you couldn’t have overlapped those procedures. You must remain mindful of the various stages of production your jobs are in.
By C.M.Wilson
