Besides having color measuring instruments with good inter-instrument agreement, standardizing the measurement procedures is of equal importance in ensuring accurate and repeatable color. This includes the method in which a sample is prepared and presented during color measurement.
Below are some general preparation and presentation best practices to ensure reliable and repeatable color measurement results.
- Ensure sample thickness, size and quantity is consistent for each measurement.
- For translucent or transparent samples, ensure light doesn’t pass through the sample by folding it. They should be folded the same number of times for each measurement. If the sample cannot be folded, use a standard plain background (e.g. white ceramic tile) and place it behind the sample instead.
- Use the same clear accessories (e.g. petri dish) each time when measuring liquids, granules, powders or other loose samples.
- For samples manufactured in elevated temperatures, take their measurements after they have cooled to room temperature to minimize color drift.
- Ensure samples are free from grease, dirt or other residue to prevent affecting the accuracy of the measurement.
- During each measurement, make sure the sample covers the entire instrument’s aperture and is flat, whether on a surface or the top of the instrument’s measurement area, or at a similar angle.
- For granules, powders or other loose samples, refills from the same batch, between measurements, for consistency.
- For patterned or multi-colored samples, place the sample in the same position and direction for each measurement. If necessary, rotate it 90 degree or change the measurement location on the sample between each measurement to obtain a more representative color.
Along with sample preparation and presentation procedures, other details like instrument model, geometry, color space and tolerance, should also be established and shared internally and within your supply chain to ensure operational efficiency.
Need help on how to develop and implement your color management process? Talk to our color specialists and let us assist you in selecting the right methodology and instruments for your measurement needs.