Ink is the essential element of inkjet printing, but it can be hard to understand how it fits into your cost equations. If you begin your inkjet journey by settling on the hardware first, your choices for ink and supporting fluids may be limited to what that vendor can provide. If you start with research into the ink characteristics that will work best for your applications, that may lead you to a specific set of vendors. Let’s look at what we mean by ink and how ink types influence cost.

Whether you are a new recruit to the world of inkjet or you have been working with the technology for years, the ink and maintenance fluids you use may still be a mystery. Because they are consumables, learning to evaluate how ink contributes to the cost of goods sold is essential for your business.

See also: Inkjet inks and important additives and  The value in OEM inkjet inks by Mark Bale

Ink and Paper Must Work Together

Inkjet printing is a marriage of ink, a fluid, and paper, a solid. How the ink arrives on the paper to create the final product combines content design, file preparation, raster image processing, print head engineering, paper transport engineering, and drying technology. Each element contributes to the final look, but ink is arguably the most critical element.

Ink’s job is to carry color to the paper and adhere. The variety of substrates, from paper to film, vinyl to fabric, is so broad that inks come in hundreds of formulations to meet the wide range of requirements. This article focuses on ink on common commercial substrates in a production inkjet environment.

Substrate – paper, vinyl, board, film -  in a production environment is a serious consideration and impacts ink economics. Work with your hardware vendors and substrate suppliers to understand the profiles of your target media. Highly porous substrates absorb ink readily, usually requiring more ink to achieve the color density required. Coated and uncoated stocks behave differently; among treated and coated stocks there are variations in how they perform with ink and printhead combinations. Vinyl and films hold the ink on the surface, sometimes needing support from primers or post-coating, depending on the nature of the ink in use.

Using moisturizers, primers, and optimizers to improve ink adhesion and reduce penetration, lowering overall ink consumption is expected. Also, it impacts the economics of print because each fluid has a cost.

Ink Type Impacts Cost in a Production World

Your favorite production printers may use pigment or dye inks or be capable of using either. Each offers different color vibrancy, lightfastness, and cost profiles. Many production printers use water-based pigment or dye inks. Still, you may also find solvent-based and UV-curable inks that add unique properties and cost considerations depending on the application.

Pigmented inks vary in cost based on how pigments are sourced and how they are milled to provide the colorant. Ink particle size impacts printability and color saturation, which is why you hear vendors talk about micromilled or nanoparticulate colorants to produce the highest level of vibrance. The smaller the colorant particle, the more vibrant and reflective it can be. The costs associated with milling and developing carrier solutions - which may be aqueous or oil-based - are expensive and contributes to how vendors price their inks. This is why aqueous dye-based inks generally cost less than pigmented inks.

Ink characteristics like viscosity and surface tension affect ink droplet formation (round, oblong, elongated), flight dynamics (clean landing or prone to satellites), adhesion to the substrate, and how much ink is needed to meet application specifications. When all ink characteristics are optimized to ensure efficient jetting for the type of print head and print applications, the result is an efficient use of the ink and consistent print quality.

Ink may not be the only fluid required to meet your print goals. You may need or want primers that keep the ink on the surface of the paper or optimizers to stabilize the ink on the sheet, and those have costs. The question that emerges is whether you should be on the search for “magic ink” that will print on any substrate or you should look for the most economical ink options and then fill in with additional fluids if needed.

To build your case for deciding what route to take in your ink selection, when options are available, assess your current ink and ink usage. Then, come back for my next post which will cover ways to make the best decision for your type of printing.