Computer-Aided Color Formulation

March 02, 2017

How many trial and error steps does it take you to formulate a color? If you answered more than three, it might be time to enlist the help of a computerized solution.

Computer-aided color formulation can bring huge benefits to your business. Out of the gate, even beginners can hit color targets faster, saving time, money and expensive colorants. Once you’ve established an accurate process, you can expect to match 95% of your color requirements within a reasonable color distance on the first try! When you consider manual mixing takes an average of 12 tries to get it right, formulation software saves labs a lot of time and money during the development and production phases.

To learn more about the benefits, check out our blog “Fast Formulation is Key to Producing Color of the Year.” Today we’re demonstrating how a portable or benchtop spectrophotometer and Color iMatch software can help you formulate paint, plastic, and textile colors faster and with less waste.

Here’s how it works.

Step One: Choose your colorants.

The amount and type of colorants you choose plays a huge role in the success of your formulation process. It’s essential to use clean and bright colorants, and the right amount of each. It’s also very important to carefully characterize colorants in the software! You know the saying:  “Garbage in, Garbage out!”

Using more colorants will increase the gamut of achievable colors. This example shows how much larger the gamut becomes when you use three green pigments in your system instead of one. However, introducing too many pigments isn’t the right solution either. It will only increase your cost and risk of metamerism. In the end it’s all about balance. As you work with your computer-aided system, you’ll learn how to make the best colorant choices to achieve fast and accurate color matches.

Step Two: Prepare your mixes and make drawdowns.

To use a color matching solution, you have to tell the software what the colorants look like. This means entering the Max Tone – the maximum colorant load vs. your resin or base material – and the solutions. For this example, I am using a 5% red with 95% clear base with a 2.5%, a 1%, and a 0.1% mix.

You must also determine the opacity by applying the mixes to white and black contrast cards and using the spectrophotometer to measure them. You can obtain this data through the contrast ratio method in iMatch.

The typical setup for one colorant consists of seven mixes + 2 optional mixes. 

Step Three: Measure the drawdowns into iMatch.

Next, you need to measure the drawdowns into the software and create the colorants. Here’s a screen image of how this looks in iMatch.

1 – This is the selection of colorants already on file.

2 – This is the colorant editor with the colorants listed at the top, and the base or resin materials at the bottom.

3 – Here are the mixes for a single colorant.

4 – And here is the colorant premix for one specific ink. Since the software knows the real scaled amounts of the mix, the measurement over light, and the measurement over dark, it can characterize the concentration with its optical property.

Step Four: Match colors with the click of a button.

Once the colorant file is ready, you really can match colors with the click of a button!

1 – The colorants are listed here in the Colorants pane. Here you can select which colorants to use, or choose to use them all.

2 – You can choose a specific base or have the software choose the most appropriate one. You can also define opacity to run to a target or run on a fully opaque layer, which means full hiding over the black area.

3 – Click “Formulate” and iMatch will give you a recipe calculation within seconds!

4 – In this example, we need 97% clear neutral base, 2.78 of white pigment, a little black pigment, some yellow oxide and some exterior red to achieve a predicted Delta E color distance of 0.02.

Step 5: Prepare the mix from the calculated formula.

It’s time to test the results! Prepare a mix and drawdown from the calculated formula and measure it into the software. Often the first attempt is close enough. If not, you can further improve the match by running a correction with just a click of a button.

Many of our customers choose to automate their dispensing processes with remote connectivity. iMatch is quite flexible in interacting with these systems and can transmit data automatically; even to production scale dispensing machines.

The system is only as accurate as your overall process!

  1. It’s very important, so I’ll say it again… the software is only as good as the original pigment calibration data. If you don’t take the time to do this right, you can’t expect good results.
  2. Consider variations in colorant batches, which can be controlled by colorant strength assessments.
  3. Keep your contrast cards stable and clean, and replace them regularly.
  4. Use an accurate scale and write down the exact measured amounts to the last decimal point.
  5. Keep in mind that sample thickness influences appearance, especially for translucent paints.
  6. Non-homogenous samples, dirt, scratches, and varying surface conditions all have an effect on the results, so be as consistent as possible.
  7. For the highest performing color matching operation, your entire production process must be reproducible. Make sure everyone is following the same procedures.

Controlling your pigment or colorant batch quality is essential.

This image shows the physical condition of the same pigments along with a microscopic image of the particles. The smaller ground pigment particles have an overall surface area that is much higher than the rough pigments. Notice the impact this has on the pigment’s appearance? You can control this through colorant strength control, something we can teach you how to do.

The Return on Investment is Amazing!

Believe it or not, 90% of X-Rite customers confirm ROI within 12 months after installing a computer-aided color matching system! If this sounds like an investment you might be ready to make, get in touch for more information.

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