Colour Index Number provides the most authoritative
way to identify dyes. |
Colour Index is the most authoritative way to search
your exact requirement of Dyes and Pigments from the vast maze of
colours offered today. Colour Index is basically a compendium of dyes.
In the U.K. the colour Index was prepared by the Society of Dyers and
Colourists, while in USA it is done by American Association of Textile
Chemists and Colorists. With the advent of the System of Colour
Indexing, many of the confusions associated with the naming and colours
of Dyes and Pigments have been effectively sorted out. |
Colour Index
The chemical names of dyes can be very confusing and
complicated. As a result of this, the practice of using names that are
descriptive has arisen. Generally a dye is referred to by a simple name
that is comprehended by people who is working with them. Which we can
say as a common name. But the problem is that it is not uncommon for a
dye to have names that are more than one. For example take basic fuchsin
which was earlier known as magenta. Taking another example it is also
quite possible that a same, or a nearly same name to be given to two
different dyes. For example light green, has also been popularly used to
refer to dye methyl green. Some of these names are historical or there
can be cases where in order to sell a single compound different
manufacturers gave different names, to avoid violating copyright or
trademarks of each other.
Above cited specific reasons in the
confusion for naming dyes, prompted a need for Colour Index. Let's first
understand what a CI or Colour Index number is. It's basically a
compendium of dyes, that has a huge volume of data. It was prepared in
the UK by the Society of Dyers and Colourists. In the USA by the
American Association of Textile Chemists and Colorists. It is available
both in the book form, and on CD as well. In this reference book there
is a very specific system to identify individual dyes. A five digit
number is assigned to each individual chemical that is used as a dye.
Consequently individual dyes get identified with reference to their CI
number only. For example when specifying a dye for use in any staining
method the CI number must be always provided. To avoid any confusion regarding chemicals, in addition to the identification number or CI number, the colour index also has a system to assign a specific name (CI Name) for each of the dyes. The name given is totally based upon the dye's mode of behaviour, base colour and action. This is followed by a number. To give an example, the CI name given for chromoxane cyanine R (CI 43820) is Mordant Blue 3. Thus the CI name therefore gives a specific way to identify a dye. Although the CI name is used less often than the CI number, the CI name is as useful in identifying a dye for a particular staining method. The following table ably illustrates the use of the Colour Index for yellow Organic pigment
Colour Index has a large number of users from a
diverse range of industries. Some of them are the following:
The following three tables highlights major
information regarding the Colour Index Part 1
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