Much of this blog series has been focused on the instrument and getting the best possible inter-instrument agreement. However, we can’t forget the basics of good practice in color measurement when it comes to sample presentation. Some types of samples can be very repeatable to present to the instrument, while others pose more challenges.
Color QC and Matching Blog
With today’s increasingly tight color tolerances and a global supply chain, it’s getting tougher to meet color specifications and tolerances. How can you be assured that when you certify instrumental color data, you can do so with confidence?
The next fundamental rule in sharing electronic color standards is that the color parameters using in the calculation of the coloriemtric data must be the same.
Using electronic color standards and sharing L*a*b* color values is the goal of many companies and their supply chains these days. It’s easy, fast, and convenient. If we’re all using the same numbers for our color target, isn’t that the best way to assure that we’re all matching to the same color? It is certainly more convenient than shipping samples around overnight. But before you do so, you need to understand the best practices of color measurement and for setting and maintaining numerical color standards. Many color disputes arise these days because color instruments don’t necessarily read the same. Electronic or numerical color standards are widely used and shared within a supply chain and have many benefits, but if all of your instruments are not regularly monitored and calibrated, then problems can arise.
CyberChrome Inc was an exhibitor at the recent American Coatings Show in Charlotte, NC. Featured products included OnColor Profiler for improving inter-instrument agreement and the OnColor Suite of color management software for quality control and color formulation.
Many users assume that since they do a daily calibration on their instrument, their readings are correct. And if they are correct, then they must match every else's. That's not usually the case. Spectrophotometers from different suppliers may read color differently. Even with the same model from the same supplier, significant differences can be found depending on the age of the instrument and how well it is maintained.
One of the more frequent questions we hear from suppliers is: What should my color tolerances be? The simple answer equates to what the client will accept in color variation in all directions of color space versus the color standard the supplier needs to match. The importance of the client providing representative color standards will be the subject of a future blog.