TAPPI T 524

Introducing TAPPI T 524 – Industrial Physics

TAPPI T 524 is a test method from the Technical Association of the Pulp and Paper Industry (TAPPI) used to measure the color of paper and paperboard. It sets out how to measure color using an instrument with 45°/0° directional geometry under a defined light source, so that results are consistent and comparable from one operator, instrument, or mill to the next.

The method is designed for finished paper and paperboard rather than pulp, and it gives quality, R&D, and operations experts a numerical way to define color – turning a subjective judgement into a measurable, repeatable specification.

What TAPPI T 524 Covers

TAPPI T 524 specifies the procedure and conditions for measuring the color of paper and paperboard. Key elements of the method include:

• Measurement using a tristimulus colorimeter or spectrophotometer with 45°/0° directional geometry
• Use of CIE illuminant C and the CIE 1931 2° standard observer
• Reporting of color as tristimulus values, and in scales such as CIE L*a*b* and Hunter L, a, b
• A defined sampling and specimen-handling procedure to keep readings repeatable

The current version is TAPPI/ANSI T 524 om-20 (2020), where “om” denotes an Official Method – a fully balloted, consensus-approved test method. A companion method, TAPPI T 527, covers the same property using diffuse (d/0) geometry rather than the 45/0 geometry used in T 524.

Why Colour Measurement Matters

Colour is one of the first things a customer notices about a paper or board product, and it carries real commercial and technical weight. A numerical color specification helps quality, R&D, and operations experts to:

• Maintain brand and product consistency across production runs and different mills
• Support clear agreement between producer and customer on what “correct” color looks like
• Control color drift caused by changes in raw materials, dyes, optical brightening agents, or fillers
• Reduce waste, rejected batches, and reprints
• Back up product development and formulation work with measurable data

Because color is easy to dispute by eye but hard to argue with once it is measured, a standardized method like TAPPI T 524 protects the integrity of both the product and the customer relationship.

How TAPPI T 524 Testing Works

In a T 524 measurement, light strikes the sample at 45° from the surface and is viewed at 0° (straight on), which excludes surface gloss from the reading. The instrument records how the sample reflects light and converts this into tristimulus values (X, Y, Z) for the defined light source and observer. From there, color can be expressed in familiar scales and as a color difference (ΔE) against a target.

To keep results repeatable, samples are built into an opaque pad of stacked sheets and multiple specimens are measured, with directional materials tested and averaged across orientations. This is the kind of controlled, repeatable approach that gives quality control teams results they can trust.

Related Standards

TAPPI T 524 sits within a wider family of optical-property methods for paper and board. Standards that are commonly referenced alongside it include:

• TAPPI T 527 – color of paper and paperboard using diffuse (d/0) geometry
• ISO 5631 – determination of paper and board color by diffuse reflectance (the ISO counterpart)
• TAPPI T 452 and T 525 – brightness of paper and paperboard
• TAPPI T 560 and T 562 – CIE whiteness and tint

Because these methods use different geometries and light sources, results are related but not always directly interchangeable – so it is important to specify which method a color figure refers to.

Instrument for TAPPI T 524 Testing

Technidyne ColorTouch®X 45 Spectrophotometer

The Technidyne ColorTouch®X 45 is a spectrophotometer built for 45°/0° directional color measurement of paper and paperboard, the exact geometry TAPPI T 524 specifies. It supports quality, R&D, and operations experts working to color specifications for pulp and paper and flexible packaging materials. 

Key capabilities relevant to TAPPI T 524 testing: 

• 45°/0° directional geometry with CIE illuminant and observer selection, including CIE C and CIE 1931 2°, matching the conditions T 524 requires 
• Touchscreen operation with pre-programmed test routines and guided calibration, so operators can run T 524 tests without an external PC 
• Reporting of color as tristimulus values and in scales including CIE L*a*b* and Hunter L, a, b 
• Trending and PASS/FAIL analysis across samples, supporting repeatable, audit-ready color control 

The ColorTouch®X 45 is also referenced against TAPPI T 452, T 646, and T 560, consistent with its use across other current Industrial Physics marketing pages for this instrument.

Explore the ColorTouch®X 45 or get in touch to talk through your TAPPI T 524 color measurement requirements.

Your Global Test and Measurement Partner for TAPPI T 524

Industrial Physics supports quality, R&D, and operations experts around the world with the paper and pulp test and measurement expertise needed to work confidently with standards like TAPPI T 524. Whether you are setting a color specification, investigating a color complaint, or developing a new grade, we can help you achieve accurate, repeatable, and reliable results.

Get in touch to talk through your paper and board color measurement requirements.