Inkjet vs. Offset: How to Specify the Best Press for Your Design

One of the biggest differences between digital inkjet and offset press technology is how ink is applied to the substrate during the print process — and, as a result, the difference in ink application bears pretty heavily on the kinds of inks and papers that are most compatible with each style of press. 

Offset presses use large films and plates to apply ink to the sheet. These plates must be fabricated before the print process can begin, and sheets that use different text and images require plates that are configured to print those specific elements. 

“The traditional offset process only produces static images,” explain Gooding and Schilling. “If you want to design a series of direct mail pieces on offset, each must be its own separate job with its own films or plates.”

Digital inkjet presses use a single-pass method of transferring ink via a fixed number of printheads that span the width of the substrate. The ink is laid onto the substrate as it is fed through the press, and, as a result, this produces more consistent coverage. 

Inkjet presses can be web or sheetfed like other more conventional print platforms, but inkjet presses can print on a wider variety of substrates, and they’re also able to streamline finishing processes like cutting, perforating, and stacking.

What’s more, the digital nature of inkjet presses makes it possible to use variable data printing (VDP) in order to produce unique, personalized pieces that can help take projects like direct mailers or catalogs to a whole new level. Plus, digital inkjet presses can run on a 24/7 basis and are able to print a wide range of projects much faster than their offset counterparts. 

The first thing to consider when weighing whether a digital inkjet or offset press is best for your application is if your project will include variable data or images. As we mentioned, offset presses are much more ideal for static print projects, in large part because of the cost associated with producing and installing separate plates for every variable component. 

This makes offset ideal for contexts that do not require significant degrees of personalization, like the book publishing industry.  

“In markets like book printing and marketing collateral, the majority of the volume is not personalized, and thus still produced using offset technology.” 

Offset presses are also well-suited for large run print jobs that do not require the use of VDP technology. For example, governmental agencies or even large healthcare providers may opt for an offset press for printing large volumes of boilerplate forms or documents. 

On the flipside, projects that require high levels of personalization via variable data are much more ideal for digital inkjet. Some examples of these kinds of projects include direct mail, transactional and critical communications, and any other instance where every piece needs to be printed with personalized data and messaging that is relevant to the recipient.

It’s also critical to consider the kind of paper you want your design printed with when determining whether to go the inkjet or offset route. The two main categories of paper are uncoated and coated, and each one presents different obstacles and opportunities for use on inkjet and offset presses. 

Uncoated paper — which is sometimes referred to as offset paper — does not use any kind of surface treatment or coating, which makes it more absorbent than other types of paper. The lack of coating means there is nothing to keep colorants on the top of the sheet. As a result, this allows more ink to penetrate the paper, and this increased degree of penetration can result in bleeding, blurry, or smudged images.

A coated sheet is one that has gone through a treatment process to coat or seal the substrate. This coating makes the sheet less porous and thus reduces the amount of ink that can be absorbed into the paper. There are two main kinds of coated paper, inkjet coated and offset coated paper. 

Offset coated paper has multiple layers of coating that are applied after the paper is manufactured, and these layers create a completely sealed, water-resistant surface. These sheets are commonly used in offset printing applications because of the ability to prevent ink absorption. On the other hand, inkjet coated paper is formulated for use with more aqueous or specialty inks that are common with digital inkjet, and this helps accommodate a broader range of colors.