What Inkjet Specifications Can Tell You

In Knowledge Base, RFP Checklist by Elizabeth Gooding

specifications…and what they can’t.

I posted an open letter to inkjet OEMs last week and got some feedback on the specifications people find most important when comparing production inkjet technology. This article is a summary of what specifications can and can’t do.

Device specifications are incredibly complex but I’m often amazed at some of the basic ones that are overlooked by buyers. For example, device footprint and weight. One or two times each year I hear of a company that bought equipment and found that it was too heavy for the floor, wouldn’t fit into the building or required a special power configuration that delayed implementation. The last one is pretty easy to fix, the first two can be really inconvenient.

Some of the specifications that might be fundamental to your operation are both easy to get and easy to understand. These include things like:

  • Duplex printing
  • Ink types (pigment, dye, UV, etc.)
  • Support for MICR or other specialty ink
  • The number of color stations (Monochrome only, CMYK or CMYK+)
  • Use of pre-coating, post-coating or spot coating

You can knock a few players off the shopping list just by getting those questions answered. After that, even things that sound simple start to get complicated. For instance, you might want toknow if the device supports paper that is as thick or as thin as you need. Since it is more common to describe papers as “heavy” or “light” rather than thick and thin, often the thickness specs are reported as GSM when they should be reported as microns (μm) which is how you measure the caliper of paper.

You can also easily narrow the list by paper feed – roll or sheet, but then you have to take the discussion to another level. For roll you will want to know about the web width, printable width and core sizes.  For sheet, you want to know the size of sheet and the printable area of the sheet. In both cases, consideration of compatibility with finishing is an important factor.

For the duplex roll fed devices, you might want to look more carefully about how they can be configured (I, L, H) which will impact how they fit on your floor and combine with finishing equipment. This information can have deeper value when you consider that some devices can run as a twin duplex printer and be dynamically switched to run as independent simplex devices – doubling the productivity of your simplex print volume (if that’s a factor in your business.)

You might be a fan of one particular print head technology over another and want to narrow your search based on that. They all certainly have their pros and cons, but heads and ink chemistry are advancing so rapidly that relying on what you thought you knew a year ago may not serve you well today.

Depending on the volume you are looking to bring onto the new equipment, you may be looking at base productivity (images per minute) as a key consideration in your search. And you might get a little frustrated trying to figure it out. You will typically be able to find print speed reported in feet per minute or meters per minute, but not everyone reports images per minute. In addition, your standard jobs may not be the same size as the standard images used to calculate IPM, in which case you are going to want to do some different math. You also want to understand the different speed/productivity options. Many devices offer a high speed mode and a high quality mode and you will get a lower productivity result with the later – sometimes considerably lower.

If you are expecting to produce high quality / high coverage material, you will also want to look very closely at the drying technology. Many devices have multiple options for dryers so that you don’t consume more energy or spend more money than necessary for the type of work that you do. You will want to understand what the standard dryer configuration is and what may cost you extra.

Which brings us to the most important thing, and the one that is nearly impossible to judge from specifications – quality. Resolution may be described as dots-per-inch (DPI) or nozzles-per-inch (NPI) but this is only one of many factors contributing to quality. You can find specs for other quality factors such as the number of drop sizes produced (gray levels) and the smallest drop size. To get even a rough comparison, you would need to know the volume of all of the drop sizes, the consistency of the drops and the level of accuracy of the RIP in communicating pixel data to instruct the print engine in placing the drops. All of those things could be measured and reported, but they still wouldn’t account for the chemistry of the ink itself or its combination with coating options.

Quality “specifications” won’t account for the emphasis on different aspects of print quality by different application segments (such as transaction printing and books) or for clients relative price sensitivity. The question you want answered at the end of your research is, “does the device deliver quality at a price that I can sell at a profit to my clients?

I don’t think a true “quality spec” exists yet – but the other data we track can help narrow the field so that you can focus your print quality comparisons on the devices that are most likely to fit your business (and through the door of your shop.)

Note: I’ve highlighted some of the specs that are currently captured in Device Finder. We look forward to adding to the base of useful data with the cooperation and support of all the great inkjet OEMs. Have an idea for data we should be tracking? Please let us know.