Zebra QLn420: Rugged 4-Inch Mobile Label Printer Product Review

Zebra QLn420

Article by Mike Monocello, editor-in-chief
Testing by Paul Aldridge, sales manager, Paragon Print Systems

A common printer in field service applications, the rugged 4-inch mobile label printer was a class of printers we were eager to test for VAR and ISV (independent software vendors) readers. For this review, we partnered with VAR Paragon Print Systems to leverage the company’s years of bar-coding expertise and facilities. To determine which printers to test, we relied on the results from January’s Best Channel Vendor survey. Using that survey data, which came from thousands of VARs and ISVs, we were able to narrow the field down to those printer manufacturers readers told us had the most reliable, feature-rich products.

On the surface, it seems as if a review of 4-inch label printers could be boring or lack any insight. After all, how much innovation and differentiation can be packed within such a small form factor? Well, quite a bit actually.

Zebra Technologies Logo Product Review

Setup & Configuration

The first thing we wanted to test was ease of setup. Specifically, we wanted to test the out-of-box-experience for someone unfamiliar with the units. Were there utilities available to set up and configure the printers for use? How easy were those utilities? Paul Aldridge, sales manager for Paragon Print Systems, found that each of the three printers tested had its own pros and cons.

All three units shipped with a Windows print driver and users’ guide on CD, as well as a printed quick-start guide for basic operation, and all three arrived with their own PC-based setup utilities. The Zebra QLn420 requires a USB cable for setup that, while not included, was easy to dig up since it’s a cable commonly used for many consumer electronics. Aldridge found the Datamax-O’Neil printer to be the most user friendly when setting up the wireless connection. The Zebra printer was close behind.

“As a ‘normal’ user, I don’t think any of the units were particularly easy to set up for Wi-Fi,” says Aldridge. “When it comes to getting these printers on a wireless network, I’d recommend someone with wireless networking expertise over printing expertise.”

Paper Loading

Another area we were eager to test was the loading of paper into the printers. For instance, how cumbersome is the experience? Is it intuitive and easy to access the media door? Aldridge found the Zebra QLn420 easy to load.

“The yellow release lever on the side of QLn420 is easy to spot,” he reports. “There are two silk-screen imprints on the printer case that highlight the proper roll direction and loading instructions.” He goes on to explain that the guides are spring-loaded and hold in place automatically. Loading a roll of labels could be completed in as little as 10 seconds. He also says that the Zebra unit’s media access door opens at the widest angle of the three, making it more accessible when loading media, especially when gloves are being worn.

Battery Life

Every manufacturer boasts about battery life and having the juice to perform over a full shift. For this test, we wanted to do something a little different by testing the number of labels that could be printed on a single battery charge. To even the playing field as much as possible, Aldridge ensured that all three printers were using new fully charged batteries and were configured the same way (i.e. Wi-Fi was enabled). The test was performed in batch mode, printing labels continuously over the wireless connection until the battery expired. The labels-printed numbers speak for themselves, but the testing also revealed some nuances in the ways these printers operate.

The Zebra QLn420 printed 1,100 4” x 6” labels (Walmart SCC-14) before the battery expired — the most labels of all three printers. The selected print speed was 3 ips and darkness was set to default. Aldridge reports that the printer pauses periodically when printing in batches to cool the print head. In fact, the VAR says that the Zebra unit paused more frequently than the other two units in batch printing mode. That said, remember that this isn’t typical operation for this type of printer, so the pausing could be a nonissue.

LCD Display

Another area we wanted to review was the LCD display. Aldridge says that all three units have an LCD display that indicates common printer conditions such as battery life, wireless connectivity, and sleep mode. “The QLn420 has a large LCD display and was the easiest to use and navigate of the three,” he says. “The display gives quick visual indication of the printer’s status in a number of key areas.”

Build Quality

As we concluded the testing, we asked Aldridge to give his thoughts on the overall fit, finish, and construction of the tested units. The VAR says that the printer’s case is curved to make it fit the body’s natural contour when worn on the hip. In fact, he felt it was the most comfortable to wear of the three. “The build quality is industrial, and the fit and finish is excellent,” he says. “However, unlike the Datamax-O’Neil and Toshiba TEC printers, the Zebra QLn420 does not stand upright on its own, a consideration if you’re looking for a cart application.” Finally, the unit has a fan-fold slot for external media loading.


As you might expect when reviewing printers from three time-tested leading manufacturers, Aldridge didn’t find much wrong with any of the units. At least, there was nothing that would blatantly disqualify a unit from being considered for your line card. Rather, there are subtle differences that might mean a lot or a little to you and your customers. In the end, it’s up to you to determine which features and functions are must-haves and which you can live without.

Read the testing methodology.

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1 year; other service offerings: A ZebraCare Depot service agreement covers all the labor and parts (excluding batteries and accessories) required to keep printers operating. Comprehensive coverage includes unlimited printhead replacement; normal wear and tear; and all internal and external components, such as the LCD, media cover, gears, etc. All Zebra equipment returned for service under these agreements will receive a complete preventative maintenance procedure and will be returned at no additional cost.

Standard with Comprehensive Agreement - The Standard agreement covers all labor and parts (excluding accessories and batteries), cleaning and adjustment, preventative maintenance, and three-day turnaround.

Advantage with Comprehensive - ZebraCare Advantage includes all the standard features with the addition of next day turnaround on all corrective maintenance.

Advantage PLUS with Comprehensive - Zebra will maintain a pool of up to 6 percent of printer inventory at our facility for same-day exchange, provide free overnight shipping, and monthly activity reports.