Calculation methods: Murray-Davies vs SCTV

To ensure a print-to-proof match, use the same calculation method as the printing press. The two methods Murray-Davies (MD) and Spot Color Tone Value (SCTV) are not interchangeable.

Gradation curves cannot be converted between methods. If you need SCTV, you must import SCTV data or create a new curve. You can, however, view curves in the other mode for comparison.

Methods overview

SCTV (ISO 20654:2017)

• Based on color measurements

• Produces more uniform visual tone steps

• Recommended for spot colors

Murray-Davies (MD)

• Based on density

• Standard for CMYK

• Limited for spot colors

Switching the calculation method

You can change the method in the Color Corrections dialog box only if:

• Tint values are available

• No corrections have been applied

The option is disabled if:

• A correction curve was loaded

• A curve was manually edited

• The library contains only full-tone values (e.g., PANTONE PLUS)

Workaround: Load a custom SCTV gradation curve.