Thursday, June 25, 2009

Color Matching for Leather Furniture Repair and Restoration

Color is one of those funny things that is extremely difficult to quantify. This is certainly true regarding color of leather furniture. There are loads of variables controlling the color you perceive, from the lighting source to the chemistry construct of the coloring agent (e.g. dye vs. pigment).

Because its so difficult to quantify, most people think in broad terms. Using brown as an example, what version of brown is in your mind's eye? Want to tighten it down further? What does Espresso or Tobacco or simply dark brown mean to you versus the person standing next to you? We all have our own personal version and we're all correct as there is no scientifically established standard, no definitive reference for color definition.

If you are attempting to repair damage on a fine leather sofa, then to conceal the repaired area the color must be exactly matched, else you'll see the difference. The human eye works on detecting contrast. If it's not an exact match, the human eye detects the differential, and draws your brain to its attention. Bingo! You can see the mismatch. Every time you look at the piece, it's what you'll see.

Close enough is not good enough.

Now to dispel a myth. Some color matcher's use a machine (spectrometer). In short, it will get you close, but never exact for a whole host of reasons. Here's the most obvious. The machine is programmed with a specific color chemistry as it's baseline. If the color chemistry you are using isn't the exact color chemistry used to program the device, the machine will interpret incorrectly. If you are painting a wall, you can get away with it, but if your color match requires precision, forget it.

Furthermore, leather furniture often has a mottled coloring technique which presents depth of color as the color variation makes the leather appear more organic. A machine can not read multiple colors simultaneously.

Once again, close enough is not good enough.

Finally there is this intriguing phenomenon known as metamerism. There are multiple versions of this affect, with the most common being the impact of a color your eye records based on the light source. Because perceived color is specific visible light wave-lengths striking your retina, the light source plays a key roll. Incandescent, florescent, halogen, arc vapor, sun all produce differing wave-lenghts. As these wave-lenghts bounce off an object and hit your eye, they influence the color you see. Do a color match under florescent lighting and then view it in sun light and you'll see the difference immediately. For a more complete definition of metamerism check out http://en.wikipedia.org/wiki/Metamerism_(color)

Once again, without the light source being considered, close enough is not good enough.

The professional leather technicians of Advanced Leather Solutions (http://www.advleather.com), color match by eye, in the lighting condition of the leather furniture's location. If that specific light condition can't be recreated, then we opt for sunlight as that provides the broadest spectral reference.

The fail-safe technique we use is very simple. Mix a color that you think you see. Then apply a piece of masking tape to the target leather. With an airbrush or other applicator, color across the leather and over the masking tape. Pull the tape up. If you detect a line, the the color is off and re-mix until you can't detect a line.
That way, you get the color matched perfectly every time.

In our leather technician's training program, it is the subject matter that requires the most time. Coloring matching can be mastered. It takes patience and practice. With experience, a technician gets better and better at it. The most difficult matches involve subtle mottling affects. In this case the technician has to interpret two colors, a base and an overlay print. The interplay of these two colors is what presents as the final color. Our do-it-yourself leather restoration (http://www.DIYLeatherSolutions.com) program success is founded on our technician's creating a custom color mix for a client so the color matches perfectly every time.

We take the guess work out by bringing our experience to the table, because we believe close is not good enough.

As an aside, over a hundred years ago, a painter/scientist named Charles Munsell developed a color quantification system using three variables, hue - value - chroma. His color system comes the closest to a standard and has been used by well-schooled colorists for decades. Check out the Munsell Color Science Labs at the Rochester Institute Of Technology to learn more. - http://mcsl.rit.edu/

Copyright 2009, Kevin Gillan

1 comment:

  1. The fail-safe technique we use is very simple. Mix a color that you think you see. Then apply a piece of masking tape to the target leather.-leather chair repair-

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