TVI Curve Inspector &middot; Inspectors &middot; ChromaChecker

TVI Curve Inspector

ChromaChecker TVI Curve Inspector — analysing tone value increase (dot gain) curves for CMYK channels, comparing against ISO 12647 targets, and identifying press curve deviations.

What Is TVI?

Tone Value Increase (TVI) — also known as dot gain — is the difference between the nominal dot percentage in the file and the actual dot percentage printed on paper. A nominal 50% dot that prints as 70% has a TVI of +20 points. TVI varies across the tonal range and differs between CMYK channels; it is a primary variable in achieving correct color appearance.

TVI Curve Inspector displays the measured TVI curve for each CMYK channel against the target curve defined by the applicable standard (ISO 12647-2, G7, or a custom curve), making deviations visible and quantifiable.

Key Capabilities

CMYK Curves

Separate TVI curve display for each of Cyan, Magenta, Yellow, and Black channels — overlaid with the target curve

ISO 12647-2 Targets

Built-in reference curves for all ISO 12647-2 paper categories (coated, uncoated, newsprint, etc.)

Custom Curve Targets

Define any target TVI curve as a reference — useful for press-specific or customer-defined standards

Deviation Highlighting

Zones where TVI exceeds tolerance are highlighted — colour-coded by severity

Historical Curve Archive

Compare current curves against previous sessions for the same device — spot curve drift over time

Curve Export

Export measured TVI data as CSV for use in curve correction software (EFI, GMG, Heidelberg Prinect, etc.)

TVI and Press Calibration

When a press deviates from its target TVI curve, the standard corrective action is to apply a printing curve correction in the workflow (RIP or CTP). TVI Curve Inspector provides the measurement data needed to calculate the required correction:

Measure a test chart with a full tonal scale (typically 0–100% in 5% or 10% steps)
TVI Curve Inspector plots the actual vs. target curve
Export the deviation data to calculate the inverse correction curve
Apply the correction in the CTP or RIP, then re-measure to verify

Relationship with G7: G7 calibration targets neutral density (gray balance) curves rather than individual CMYK TVI curves. Use TVI Curve Inspector to verify individual channel behaviour; use G7® Curve Inspector to evaluate gray balance and NPDC compliance.

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