Printing on coated paper refers to the process of using paper substrates that have a specially designed coating for water-based inks used in inkjet printing onto maintain throughput levels needed for production scale digital printing.
Traditionally, to maintain consistent inkjet printing that can effectively balance ink absorption and surface retention is by using specially coated papers that create a consistent, universal surface on the paper or adding primers to affordable offset coated papers. However, both these methods invite additional complexity and expenses in production environments.
Why do most inkjet presses require specially coated papers or primers?
Most production inkjet presses use aqueous inks, meaning the primary carrier fluid is water mixed with pigments and specialised additives. Water plays a critical role because it dissolves the pigments, enables the low viscosity required for the extremely small ink droplets used in drop-on-demand processes, but must then be evaporated during drying to leave the colourant fixed to the substrate. However, water’s chemical properties also make it highly absorbent and capable of penetrating porous materials like paper easily. If too much of the ink is absorbed below the surface of the paper, the colourant becomes embedded within the fibres and the resulting image appears muted as the substrate influences the perceived colour more.
Different paper types absorb liquid at different rates depending on their porosity, which refers to the microscopic spaces within the material that can draw in fluid. Because each substrate behaves differently, many early production inkjet systems relied on specially coated papers designed specifically for digital printing. These papers often use nanoporous coatings that trap pigment particles near the surface while allowing the carrier liquid to absorb or evaporate rapidly. This approach can produce excellent image quality, but the specialised coatings significantly increase paper cost and limit the range of compatible substrates.
Another common solution has been to apply a primer to offset-coated papers before printing. Offset papers dominate the commercial printing market because of their long history in production printing and today are widely available and relatively affordable. However, their mineral coatings are engineered for oil-based analogue inks and tend to repel water-based inkjet fluids. Therefore, a primer layer must be applied before printing to effectively create a new surface on top of the paper coating. This layer ensures consistent droplet placement, stabilises absorption rates, and improves drying behaviour to enable consistent, reliable printing output that can be sold for a profit and support the business’ growth.
While priming makes offset papers compatible with inkjet systems, it introduces additional complexity. The priming process requires its own equipment, consumes additional materials, and adds another stage to the production workflow. Each of these factors increases operational cost and can slow overall throughput.
How does Truepress SC Ink enable printing on offset-coated paper without primer?
SCREEN’s Truepress SC Ink was developed to address the limitations of traditional inkjet approaches by enabling high-quality printing directly on standard offset-coated papers without the need for primer. The formulation contains specialised binding components that interact with the mineral coating on offset substrates, allowing pigment particles to remain near the surface where they can produce strong colour density and sharp image detail without the additional costs of specially coated inkjet papers.
By eliminating the need for primer, the printing process becomes significantly simpler. Removing this step reduces the number of components required in the production line and eliminates the time required to prepare and dry the primed surface. The press can therefore move more quickly from file preparation to printing, improving efficiency across the entire production workflow.
Another benefit of this approach is improved compatibility with existing printing environments. Many commercial printers operate both offset and digital presses to handle different run lengths or applications. Because Truepress SC Ink allows the same offset-coated papers to be used across both technologies, businesses can standardise substrate inventories and reduce the complexity of sourcing multiple specialised papers across different production or finishing lines.
Why is printing on offset-coated paper valuable in production printing?
The ability to print directly on offset-coated papers represents a significant advantage for production inkjet systems because these substrates are already widely used across the commercial printing industry. By supporting these materials without additional treatment steps, production inkjet presses can integrate more easily into existing print operations while maintaining competitive operating costs.
Solutions such as SCREEN’s Truepress SC Ink demonstrate how advances in ink formulation can remove barriers that previously limited the economic efficiency of inkjet printing. By enabling high-quality results on widely available coated papers while reducing energy consumption, equipment complexity, and material waste, modern inkjet technology can deliver both operational and sustainability benefits within high-volume production environments.