Delta Finder

This tutorial explains how to compare two colors.For example a measured color and a Pantone value from a digital color chart.

The Delta E makes it possible to quantify the difference between two colors.But if you want to know more about what Delta E is, we encourage you to check out the Wikipedia article:https://en.wikipedia.org/wiki/Color_difference (English version is more complete)

If a Delta E number is less than 1 between two colors that are not touching, it is barely noticeable by the average human observer.A Delta E between 3 and 6 is generally considered an acceptable number in commercial reproduction, but the difference in color can be seen by printing and graphics professionals.The Delta E Finder module is able to compare two types of files:.spc: A color measured with a spectrophotometer. The file contains the measured spectral values.

In this tutorial, we are going to compare a sample measured on a "Fan" type paper Pantonier, with the Lab value of this same Pantone, but coming from a PANTONE digital color chart.

Read a PANTONE® sample with your spectrophotometer

In this example we will be using a PANTONE® color from a color table.To use this PANTONE® color table you must have an appropriate license.

The best way to get it is to buy a Formula Guide from PANTONE®. Each purchase of Formula guide gives you access to a code to download its digital version from the PANTONE® COLOR MANAGER software.

For more information, see chapter: Capture of a Color

Import PANTONE C digital color chart

To import a color table, you just have to drag it into the files column on the left.

For more information, see chapter: Color table

Import a selected color from a table to the files column

In your PANTONE® table, indicate in the search bar, the reference of the chosen color, then drag the color in the column of files on the left.

How to get the Delta E between two colors?

The last step is to select one of the two colors, open the Delta Finder module and then drag the second color into the "Color" field of " Delta Finder ".

The Delta E value will be displayed just below.In our example the Delta E00 between the reference value of the PANTONE 7726 C and the value of the measured sample is 1.4

Choice of the Delta E calculation method

Conclusion

PANTONE® paper color charts are less accurate than their digital versions because printed versions cannot be reproduced with absolute values, let alone wear and tear from handling.In addition, measurement with a spectrophotometer is more precise and is not disturbed by the ambient environment unlike a visual comparison (Observation under a bad light source for example).