Mastic Aluminum Coil and Mastic Aluminum Trim Coil Color Difference Standards 

In the procurement and application of mastic aluminum coil, color difference control is a crucial link to ensure product appearance uniformity and project acceptance rates, with industry standards serving 

as the core basis for determining whether color difference is qualified. Buyers often face questions such as "How to set color tolerance?", "What constitutes a standard inspection process?", and "Which 

standard should be applied in different scenarios?". This article systematically reviews domestic and international industry standards related to color difference for mastic aluminum coil, breaking down 

quantitative indicators, inspection specifications, and scenario-based application points to provide professional guidance for procurement and quality control.

First, it is essential to establish a core understanding: color difference in mastic aluminum coil is not unregulated but is governed by clear domestic and international industry standards that serve as 

quantitative and inspection criteria. Since the mastic color is a light beige-yellow tone, it is more sensitive to color deviations. In practical applications, it is necessary to refine control requirements within 

the standard framework according to its hue characteristics, rather than directly applying general color standards.

The core industry standards for color difference control of mastic color coated aluminum coils are currently divided into two major systems: domestic national standards and international European 

standards. Together, they form the mainstream compliance basis within the industry.

Industry Standards and Specifications for Mastic Aluminum Trim Coil Color Chart

Mastic Aluminum Trim Coil Color Chart: Key Industry Standards and Specifications 

Domestic Core Standards: GB/T Series Standards

 GB/T Standards for Mastic Aluminum Trim Coil Colors 

In domestic procurement and acceptance, the two most commonly used standards are GB/T 11186.2 and GB/T 23443-2009. They have clear divisions of labor, covering different application scenarios:

—GB/T 11186.2 "Methods for Measuring the Color of Paint Films Part 2: Color Measurement": As a basic universal standard for color difference inspection, it clarifies the core principles, instrument 

requirements, and environmental conditions for measuring color difference in mastic aluminum coil. This standard stipulates the use of the CIELAB color space for color difference calculation, with 

the ΔE value (total color difference) as the quantitative indicator. It provides a unified measurement benchmark for subsequent color tolerance settings and is the prerequisite basis for all color difference

 inspections of mastic color.

—GB/T 23443-2009 "Aluminum Single Panel for Building Decoration": For building decoration scenarios, this standard specifies a relatively lenient tolerance range of "color difference ΔE ≤ 2 NBS for 

single-color coatings." However, it is important to note that the mastic color, as a light yellowish base, is visually more sensitive to color differences. Direct application of this standard may result in

 perceptible deviations to the naked eye, affecting the uniformity of the project's appearance. Therefore, the industry often combines the characteristics of the mastic color to tighten the tolerance 

based on this standard, forming more suitable control requirements.

International Core Standard: EN 13523-3:2014

European Standard EN 13523-3 for Mastic Aluminum Coil 

For export orders or high-end projects, the European standard EN 13523-3:2014 "Coil Coated Metals - Test Methods - Part 3: Colour Difference - Instrumental Comparison" is often followed. This standard is 

more stringent in inspection details. Not only does it specify the CIELAB color space and ΔE quantitative method consistent with GB/T 11186.2, but it further refines measurement parameter requirements. 

For example, the measurement wavelength range must cover 400nm-700nm with intervals not exceeding 20nm. It also provides clear guidance for the measurement mode of textured coatings, making it 

more suitable for mastic aluminum coil which may have slight textures.

Scenario-Based Color Tolerance Standards for Mastic Aluminum Trim Coil Colors

 Application-Specific Tolerance Standards for Mastic Aluminum Trim Coil Colors 

Based on the above standards and the light tone characteristics of the mastic color, the industry has developed scenario-based color tolerance specifications. These comply with the standard framework 

while meeting practical application needs:

Standard Tolerance for General Engineering Projects

General Tolerance Standards for Mastic Aluminum Trim Coil 

1. General Engineering Scenarios (Ordinary Building Decoration, Standard Appliance Housings, etc.): It is recommended to agree on ΔE ≤ 1.5. This standard is based on GB/T 11186.2 and refined according 

to the characteristics of the mastic color. At this level, the color difference is basically indistinguishable to the naked eye, fully meeting the acceptance requirements of general scenarios. It is also the 

mainstream tolerance standard for mastic aluminum coil procurement within the current industry, effectively avoiding site rejections or appearance disputes.

2. High-Precision Scenarios (Brand Chain Store Decoration, High-End Appliance Manufacturing, etc.): It is recommended to tighten to ΔE ≤ 1.0. This standard references the stringent requirements of 

EN 13523-3:2014 and is suitable for scenarios with extremely high demands for color consistency. It maximizes the visual uniformity of batch products and avoids color difference perception caused by 

environmental lighting changes. However, it should be noted that this standard requires suppliers to improve production process control precision, which will correspondingly increase production cycles 

and costs.

Standard Implementation: Core Standardized Inspection Process

Mastic Aluminum Coil Inspection: Standardized Color Measurement Process 

The effective implementation of industry standards relies on a standardized inspection process. Otherwise, even if tolerance ranges are agreed upon, non-standard inspections may lead to distorted results.

 Combining GB/T 11186.2 and EN 13523-3:2014, color difference inspection for mastic aluminum coil must strictly adhere to the following requirements:

Environmental and Instrument Requirements

Key Parameters for Measuring Mastic Aluminum Trim Coil Colors 

1. Environmental Requirements: Inspection must be conducted in a standard environment of (23 ± 2)°C and relative humidity (50 ± 5)% to avoid measurement deviations caused by changes in coating 

state due to temperature and humidity fluctuations.

2. Instrument and Parameters: Use a calibrated colorimeter with an integrating sphere measurement mode (d:8° or 8°:d) to accommodate any slight texture in the mastic color. The measurement 

wavelength range must cover 400nm-700nm with intervals not exceeding 20nm to ensure the accuracy of measurement data.