中文
Search
Close this search box.
Ranbar pigment and dye logo

International Color Index Number (C.I.)

what is color index?

The International Color Index (C.I.) is the most widely accepted and used system globally for naming and classifying dyes and pigments. This system standardizes and categorizes various dyes and pigments by assigning a unique number to each color, making it an internationally recognized authoritative reference standard.

The Color Index database contains extensive information about dyes and pigments, including their chemical structures, manufacturers, application fields, and safety data. To date, the index system has registered over 13,000 Color Index Generic Names (CIGN), covering more than 34,500 dyes and pigments. As new dyes and pigments are continually developed, this number will continue to grow.

Color Index

Management and Publication of the C.I. System

The Color Index (C.I.) system is managed and published in collaboration by the Society of Dyers and Colourists (SDC) in the UK and the American Association of Textile Chemists and Colorists (AATCC). These organizations ensure that the system is regularly updated to include new dyes and pigments, reflecting the latest developments in the field. The C.I. system provides comprehensive and authoritative information on the classification of dyes and pigments, offering a valuable resource for those needing to find generic names, chemical structures, suppliers, and technical applications of colorants.

Classification Method of Color Index Numbers

The International Color Index (C.I.) uses a dual classification method: the Color Index Generic Name (CIGN) and the Color Index Constitution Number (CICN). Each dye or pigment with a Color Index Generic Name corresponds to a Color Index Constitution Number.

International Color Index Management Association SDC and AATCC logo

Color Index Generic Name (CIGN)

The CIGN describes the dye or pigment based on its common commercial use category, color, and a sequence number. The sequence number is generated based on the order of registration. For example, in C.I. Pigment Violet 19, “Pigment” denotes the commercial category as a pigment, “Violet” indicates the color, and “19” is the registration number for that specific violet pigment. C.I. Pigment Violet 19 is a quinacridone violet pigment.

Color Index Constitution Number (CICN)

The CICN is a five- or six-digit code used to differentiate colorants with distinct chemical compositions. Before 1997, a five-digit code was used. However, due to the emergence of many new dyes and pigments, the code was expanded to six digits to prevent duplication. If the chemical composition varies only in the metal or acid radical of a compound, a colon and an additional number are added to the six-digit code for differentiation.

In the process of continuous updating and development, the International Color Index (C.I.) system has become the cornerstone of the dye and pigment industry, providing a common language and framework for manufacturers, scientists, and designers worldwide. The widespread application of this system has facilitated technological advancements and innovations in the field of dyes and pigments, driving the development and application of new types of dyes and pigments.

Leave a Comment

Your email address will not be published. Required fields are marked *

Shopping Cart
Scroll to Top

Schedule Appointment

Fill out the form below, and we will be in touch shortly.