| Points of Difference |
Dyes |
Pigments |
| Solubility |
They are soluble |
Pigments are colourants that are insoluble in water and most of the
solvents |
| Number |
Available in Large number |
Comparatively lesser in number |
| Product resistance |
Lower as compared to pigments |
Very high |
| Lightfastness |
Lower Dyes are very much vulnerable. Lights destroy colored objects
by breaking open electronic bonding within the molecule |
Traditionally pigments have been found to be more
lightfast than dyes |
| Size |
Dye molecules are comparatively smaller it's like
comparing a football (pigment) to say a head of a pin (dye) |
Pigment particles are about 1-2 microns in size. (1 micron =1/1000
meter). It means that the particles can be seen under a magnifying glass |
| Bonding |
Taking the example of dyeing a wood surface, the dye
and the substrate (wood) that is dyed are chemicals, that have certain
features called functional groups. At the level of molecules these
groups serve as open pockets of electrostatic charges (+ or -). The
functional group in dyes, serve as a method for attaching the dye to the
wood |
For example taking the example of a wood surface
Pigment requires the help of a binder for gluing. As it is an inert
substance which is merely suspended in a carrier/binder |
| Structure during the application process |
During application process there is a temporary alteration in the
structure of the dyes |
During application, pigments have the capacity to retain
particulate or crystalline structure |
| Imparting of Colours |
Dyes can only impart colour by selective absorption of the dyes |
Pigments impart colours by either scattering of light or by
selective absorption |
| Combustible properties |
Taking the example of a Candle making process, if the
candles are dyed it is easily combustible and can be applied throughout
the candle |
In the example of a candle making as pigments are colored
particles, they tend to clog a wick when burned. This makes them
undesirable for a candle if it is colored throughout and used for
burning |
| Chemical Composition |
Usually the dyes are organic (i.e. carbon-based) compounds |
While pigments are normally inorganic compounds, often involving
heavy toxic metals |
| Longevity factor |
The dye based printing inks do not last as long as the pigment inks |
In case of ink based printing prints made with pigments lasts
longer |
| Printing on substrates |
Compatible with almost all the substrates that needs
to be dyed |
Owing to the physical makeup of the pigment inks the range for
suitable substrates are limited |
| Colour gamut |
Taking the case of printing inks, dye based inks
offers a wide variety |
As compared to dye-based inks, pigment inksets somewhat lags
behind, on the same paper stock |
