Pigment inks

Lightfast Printing with Pigment Inks

Unlike water-based dye inks, pigment inks are suspended in other types of solvents. However, the term dissolved is not really correct in this case, because a key characteristic of pigment ink is that the color pigments do not actually dissolve in the carrier liquid, but are only finely dispersed within it.

Pigment inks get their name from these color pigments—small particles of the coloring agent that float in the solvent. The pigments are typically between 50 and 150 nanometers in size, whereas the molecules in water-based inks are only about two nanometers in size.

A nanometer is one billionth of a meter

Differences Between Dye Ink and Pigment Ink

The main difference, as explained above, is that pigment ink consists of a dispersion in which the pigments are finely distributed. Common solvents include alcohol or ethyl acetate.

In dye inks, the colorants are chemically dissolved or bound as complexes. This leads to the respective advantages and disadvantages of pigment and dye inks.

Water-soluble inks remain water-soluble even after printing or writing. This means they are not waterproof, and the color will blur when exposed to moisture.

When printing with pigment inks, a layer forms on the print medium after the solvent evaporates. This layer is lightfast and largely water-resistant.

Solvent-based inks dry faster than water-based inks, regardless of temperature and humidity. For this reason, they are especially used in countries with high humidity when printing on smooth surfaces.

However, on thin paper they can easily bleed through, making the reverse side unusable.

For smooth surfaces such as glass, metal, or films, solvent-based pigment inks are also well suited in our regions.

Advantages of Pigment Inks

The greatest advantage of pigment ink is certainly its color stability and lightfastness. Its durability on a print medium distinguishes it from water-based inks.

Prints made with pigment ink produce a sharper image and achieve higher color brilliance. In the case of small printed text, the lettering is much easier to read when printed with pigment ink.

In addition, the prints maintain the same quality even over many years.

Due to the solvent used, pigment ink dries faster than water-soluble ink. This is particularly important in processes such as stack printing.

Disadvantages of Pigment Inks

Since pigment ink is always a dispersion, the pigments can settle over time, making the ink unusable. Before use, the ink must be re-dispersed. If this is no longer possible, the ink can no longer be used.

This property significantly limits the shelf life of pigment inks.

Printer nozzles also clog more quickly with pigment inks than with water-based inks due to the larger particles.

Because pigment ink does not penetrate into the printing medium but instead remains as a layer on its surface, certain surface effects cannot be achieved with it.

Films from Bleher Folientechnik Printable with Pigment Ink

optimont® inkjet films are made from biaxially oriented PET, also known as BOPET carrier film. This film is heat-resistant and highly tear-resistant.

It is coated on one side with a layer that can be printed using inkjet inks, including pigment inks. The coating absorbs the pigments from pigment ink as well as the colorants from dye inks.

In addition, the rough coating ensures a short drying time, which is important for stack printing processes.

Inkjet printers achieve very high-quality printing results with pigment ink on optimont® inkjet films.

Bleher’s Range of Films Suitable for Pigment Inks

Bleher Folientechnik GmbH offers inkjet films in standard formats such as A4 and A3. We also supply US letter format, special custom formats, and films in roll form.

This allows you to work with inkjet printers using single-sheet feeding or to operate printing machines with stack processing.

For optical sensors used for sheet detection in inkjet printers, we also provide special versions of optimont® inkjet films.

Pigment Ink in Inkjet Printers and on Photo Paper

As already mentioned, printer nozzles can clog more easily when pigment ink is used. It is therefore important to ensure that a pigment ink is suitable for a specific printer model.

If unsuitable inks are used, the result may be streaky or blotchy prints. Extensive printhead cleaning procedures, which consume a lot of ink, or even the expensive replacement of a printhead, can be the consequences.

When printing on photo paper, you should also make sure that the photo paper is compatible with the printer inks. Special pigment inks designed for printing on photo paper ensure brilliant print results.

FAQ