Methodology

Everything we can think of...

Art material

What you see on our website as a representation of a brand's color "Gradient swatch" and also our "Masstone swatch" which is the basis of color measurement and color plane visualisation, is a one-time sampling.

• We cannot be sure that all brands keep all their colors consistent over time (between batches or on the long run).
• Storage can affect the conditon of tube colors, and color can be affected by how much binder is in the sample.
• The same color can look different or behave differently if it comes from the tube / pan / dot card.

Paper

Paper can affect color with its

• Own color (especially when used with more transparent mediums)
• Texture (how it accepts color and reflects light)
• Thickness / Structure (how it lets through light to the surface below when measuring)

We use natural white paper with no optical brighteners, suitable for the mediums.

Read more about our papers at "How our color samples are made (masstone)"

Sample / Application of art material on paper

How one uses art materials can be very unique to that person.

With our masstone samples, we need to make them as opaque and even as possible with normal use of the medium on quality paper. We use different papers, tools and techniques suitable for the medium and try to be consistent.

• All these differences matter more in the case of certain mediums and colors.
• Masstone can be dramatically different from how one usually thinks of a color (it's typical hue and lightness) or its undertone.

Most of our samples are our hand made masstone swatches.

Some exceptions are mediums which wouldn't be available for us for sampling and we decided to use their painted color charts as source.

Read more about our masstone swatches at "How our color samples are made (masstone)"

Device

Color sensor devices can simulate different observation and lighting conditions, so it's important to know what measurement geometry, observer and illuminant was used for the color measuring to be able to interpret the results.

Measurement modes can also vary and define the presence or absence of UV light or (with certain geometry like D/8 and D/0) surface reflections.

Specs include

• Light source
• Illuminant
• Observer
• Spectral range
• Measurement geometry
• Measurement aperture
• Measurement modes

Devices have different accuracy and precision (Inter-Instrument Agreement and Repeatability) and they usually offer white tile calibration, which is essential.

Read more about our devices at "How we measure colors (devices)"

Circumstances

• Temperature can affect certain mediums and extremities could affect measuring devices too.
• Surface color and texture beneath the sample can affect measuring.
• Uneven and transparent samples will be more affected by paper color etc. and the exact spot of measuring.

Our color data is measured on masstone swatches (made as opaque as possible with normal use of the medium and the specific brand on quality paper). You can find these samples on the individual pages of brand colors.

Application

• For watercolor and ink, we use a brush to paint a concentrated, full-strength sample. (Dry pigments are also made into watercolors with a store-bought watercolor medium.)
• For gouache and acrylic, we use a palette knife to paint a tube color sample.
• For colored pencils, we use medium pressure for shading, and aim for a good even coverage.
• For dry pastels, we don't use any special tools, just the art material itself (and how much the paper can comfortably take).
• For oil pastels, we occasionally use a palette knife when the surface needs to be evened out.

Currently we only have dry masstone samples for water-soluble mediums like water-soluble colored pencil or pastel.

We use the following algorithms and software components

• Basic conversion algorithms based on the math from EasyRGB
• Chromatic adaptation algorithms based on matrices from Bruce Lindbloom's page
• Conversions / interpolation between CIELAB, CIECAM02, Munsell: color-science/color Python package
• Client side calculations: Culori.js.

In our color managed workflow

• We scan images with an Epson V600 scanner using Silverfast SE Studio 9 (and our own color targets)
• Scanned images are saved as TIFF files to Adobe Lightroom Classic in ProPhoto RGB color space
  (Epson's MacOS software Epson Scan 2 can only create 8-bit files in Adobe RGB)
• Processing is done with Adobe Photoshop in ProPhoto RGB
• Images are corrected for white balance and
• Sliced to a set size for swatches with a PS script which also pairs the resulting images with records in our database
• Images are exported as sRGB JPEGs and Display P3 PNGs (16-bit) and uploaded to our server / website
• Displayed masstone images are proofed for matching the measured spectrophotometer color data of the same swatches (using ImageMagick for determining dominant color) and
• Swatches with too much color difference (resulting from scanning or gamut mapping) are revised and corrected for color by hand (modifying RGB data in their color matrix or hue, saturation, brightness using ImageMagick)

(Results are optimized for display in sRGB and Display P3)

Database revision is currently in progress

Monitors used

• iMac
• BenQ SW272U

You can read about "How we scan and process images" above.

Scanned images are processed and exported as sRGB JPEGs and Display P3 PNGs (16-bit), and depending on your display gamut you see the best possible format.

See also Color support in browsers / Your display gamut →

The data sources for the color navigators are:

• HLC Colour Atlas by freieFarbe e.V. (Creative Commons license CC-BY-ND 4.0)
• Munsell Renotation Data: Munsell Color Science Lab Educational Resources / RIT

There are some other great sources available for color notations for artist materials:

1. Watercolors: CIE L*a*b* and CIECAM02 values for watercolors are available on handprint.com.
2. Oil: A Munsell explorer is available on colorwell.org.
3. Pastels: Almost 3000 Munsell notations for pastels are available on Paul Centore's An Artist's Guide to Pastel colors page.
4. Different mediums: Multiple artist brand's CIE readings available on freiFarbe under `Open color Systems Collection (OCSC) 2.0`.
5. Different mediums: Color Mixing Tools contains measured data for many paint lines.

For some (mostly Japanese) brands it's common practice to have Munsell values on their color charts.

Yes, for personal use (see the licence below). You can download data (including pigment and color notation information) in xlsx or json format from the individual brand pages. You can also download your collections.