Exercise Book Anti-Myopia Performance Testing: Standards, Methods, and Technical Requirements

Exercise book anti-myopia performance testing evaluates the optical, colorimetric, and print-quality characteristics of student workbooks that influence visual comfort during prolonged reading and writing. Based on GB/T 43011-2023 and a suite of supporting ISO and GB paper-testing methods, accredited third-party laboratories measure parameters such as lightness, chromaticity, ISO brightness, fluorescent whitening agent contribution, gloss, opacity, and ruling-line quality. The resulting data help manufacturers, publishers, schools, and regulators verify that exercise books genuinely support eye-care and myopia-prevention claims.

Technical Overview

Myopia has become one of the most significant public health concerns among school-age children, and sustained near-distance work such as reading and writing is recognized as a major contributing factor. Because students spend several hours per day using exercise books, the physical design of these products directly affects the visual load they experience: the lightness and color tint of the paper, the amount of specular gloss, the presence of optical brighteners, and the color, width, and durability of the ruled lines all influence glare, contrast, and visual fatigue.

GB/T 43011-2023, the Chinese national standard specifying test methods for the myopia prevention performance of exercise books, provides a reproducible laboratory framework for quantifying these characteristics. The standard does not certify a medical outcome; instead, it verifies the measurable design attributes associated with reduced glare and improved visual comfort, most notably moderate lightness with a warm chromaticity, a controlled level of fluorescence, low gloss, adequate opacity, and high-quality ruling.

Testing under this framework is supported by an established family of paper and board test methods, including brightness determination (ISO 2470 series, GB/T 7974), color measurement (ISO 5631, GB/T 7975), opacity (ISO 2471, GB/T 1543), specular gloss (GB/T 8941), bending stiffness (ISO 2493-1, GB/T 22364), conditioning atmospheres (ISO 187, GB/T 10739), and sampling (ISO 186, GB/T 450). Product quality and safety aspects of exercise books are additionally covered by QB/T 1437 for school exercise books and GB 21027 for the general safety of student supplies.

Testing Samples

Finished Exercise Books

Complete, retail-condition workbooks are tested as received, including the cover, inner pages, and ruling. Testing on finished books captures the combined effect of the base paper, printing ink, and converting processes, and is the basis for verifying anti-myopia claims on the final product.

Base Paper and Printed Sheets

Paper mills and book manufacturers may submit base stationery paper or printed ruled sheets prior to binding. Testing at this stage supports incoming quality control, paper grade qualification, and process optimization before mass production.

Sampling and Conditioning

Sampling is performed in accordance with GB/T 450 (ISO 186) to ensure the submitted items are statistically representative of the production lot. Test pieces are taken from areas free of wrinkles, folds, watermarks, and printing defects, avoiding edges of the sheet. All specimens are conditioned to equilibrium in the standard atmosphere of 23 °C ± 1 °C and 50 % ± 2 % relative humidity as required by GB/T 10739 (ISO 187) before measurement. A typical submission consists of 10 to 20 finished books or an equivalent quantity of paper, with multiple test pieces measured for each parameter to obtain statistically meaningful results.

Testing Items

The testing program covers the optical properties of the paper and the print quality of the ruled lines, which together determine the visual comfort performance of the exercise book:

• Lightness (L*) and chromaticity coordinates (a*, b*) of the paper surface, including dominant wavelength analysis
• ISO brightness (R457 diffuse blue reflectance factor) of the paper
• Fluorescent whitening agent contribution, determined as the difference between brightness measured with and without UV excitation
• Specular gloss of the paper surface, typically at 75° geometry
• Opacity (paper backing method)
• Color coordinates of the printed ruling lines and line-to-paper contrast
• Ruling-line width and width uniformity across the page
• Print durability and rub resistance of the ruling lines
• Bending stiffness of the inner pages
• Derived glare-related indices combining brightness, gloss, and chromaticity data

Testing Methods

Lightness and Chromaticity of the Paper

The lightness and chromaticity of the paper surface are measured with a calibrated spectrophotometer using diffuse illumination and normal viewing (d/0) geometry under the D65 illuminant with the 10° standard observer, following the principles of GB/T 7975 (ISO 5631). Multiple readings are taken on unprinted areas of the inner pages from several books, and the mean values and standard deviations are reported. Eye-friendly exercise book paper is characterized by moderate lightness and a warm, cream-toned tint rather than a stark blue-white appearance.

ISO Brightness and Fluorescent Whitening Agent Evaluation

ISO brightness is determined as the diffuse blue reflectance factor at 457 nm in accordance with GB/T 7974 (ISO 2470-1), which includes the contribution of any fluorescent whitening agents present in the sheet. A companion measurement is performed with the UV component of the illumination excluded, consistent with ISO 2470-2. The difference between the two results quantifies the fluorescent whitening agent contribution. Excessive fluorescence is associated with increased perceived glare under bright classroom lighting and is therefore a key rejection criterion in eye-care paper design.

Specular Gloss

Surface gloss is measured with a glossmeter at a 75° geometry in accordance with GB/T 8941. Low specular gloss prevents mirror-like reflections of ceiling lights and windows from reaching the student's eyes, reducing squinting and glare-related fatigue. Measurements are taken at several positions on both sides of the sheet, and the average value is compared against the specification for low-glare stationery paper.

Opacity

Opacity is measured using the paper-backing contrast method in accordance with GB/T 1543 (ISO 2471). Insufficient opacity allows writing on the reverse side to show through, which degrades legibility and forces the eyes to work harder to distinguish the intended text. Inner pages of exercise books are expected to provide adequate opacity to maintain a clean writing surface.

Ruling-Line Quality

The color of the printed ruling lines is measured with a spectrophotometer or colorimeter, and the contrast between the line color and the paper color is expressed as the difference in CIE lightness values. Line width and uniformity are assessed using a calibrated optical microscope or image-analysis system at defined magnification, with measurements distributed across the page to detect variation between the beginning and end of the printing run. Soft-toned lines with moderate, consistent contrast are preferred over harsh high-contrast rulings for sustained writing comfort.

Rub Resistance of Printed Lines

The durability of the printed ruling is evaluated using a standardized rub or abrasion test. Lines that smudge or transfer during normal handling and erasing degrade page legibility over time and increase visual strain from re-reading unclear text.

Bending Stiffness

The bending stiffness of the inner pages is determined using a two-point bending method in accordance with ISO 2493-1 (GB/T 22364). Pages with adequate stiffness lie flatter during writing, which helps maintain a stable viewing angle and a healthy distance between the eyes and the page.

Data Processing and Reporting

For each parameter, the laboratory reports individual values, means, standard deviations, and a conformity statement against the applicable specification limits. Reports issued by accredited third-party laboratories also document the test conditions, instrument calibration status, referenced standards, and photographic evidence where relevant, providing a defensible technical basis for product claims and procurement decisions.

Applications

Anti-myopia performance testing of exercise books serves multiple stakeholders across the education and stationery supply chain:

• Paper mills developing and qualifying eye-friendly stationery paper grades with tuned lightness, tint, and fluorescence levels
• Exercise book manufacturers performing incoming paper inspection, print process control, and final product release testing
• Brand owners and publishers substantiating eye-care and anti-myopia marketing claims with independent laboratory evidence
• Schools, education authorities, and government procurement agencies verifying supplier conformity during tendering and acceptance inspection
• Market surveillance bodies checking whether commercially available exercise books meet the declared optical performance requirements
• Exporters and international buyers requiring third-party technical documentation for back-to-school stationery products

FAQ

What does "anti-myopia performance" mean for an exercise book?

It refers to a set of measurable optical and print characteristics, such as moderate lightness, warm chromaticity, low fluorescence, low gloss, adequate opacity, and clean consistent ruling, that are associated with reduced glare and lower visual fatigue. Testing verifies these design attributes; it does not constitute a medical guarantee that using the product will prevent myopia.

Which standard governs this testing?

GB/T 43011-2023 specifies the core test methods for the myopia prevention performance of exercise books. It is applied together with supporting methods including GB/T 7974 (ISO 2470-1) for brightness, GB/T 7975 (ISO 5631) for color, GB/T 1543 (ISO 2471) for opacity, GB/T 8941 for gloss, and ISO 2493-1 for bending stiffness, while QB/T 1437 and GB 21027 cover product quality and safety aspects.

Why is extremely white paper considered undesirable?

Very high ISO brightness, frequently achieved through fluorescent whitening agents, produces strong glare and harsh contrast under typical classroom lighting. Warm-tinted paper with moderate brightness diffuses light more comfortably and reduces the accommodative stress experienced during prolonged writing.

What samples and quantities are required?

A typical submission comprises 10 to 20 finished exercise books from the same production lot, or an equivalent quantity of base paper or printed sheets for pre-production evaluation. Specimens are conditioned at 23 °C and 50 % relative humidity before measurement, and multiple test pieces are measured for each parameter.

How long does a typical test cycle take?

After sample conditioning is complete, a full testing program covering paper optical properties and ruling-line quality is generally completed within five to ten working days, depending on the scope of testing and the number of parameters requested.