I inherited a DYMO 400 label printer that has a simple USB connection, but it has recently lost the Windows support lottery. My goal was to convert this old standalone label printer (Figure 1) into a network label printer that all the computers on my network can access. Linux users often chafe at the need to replace hardware that is still functioning perfectly well, so keeping an old printer going is a problem that many of us have faced in the past. In this case, it actually appears that the old version of the printer might function better than the newer model (see the box entitled "DRM Woes"), so I'd prefer to keep using it.

Figure 1: The DYMO 400 label printer.

The Linux ecosystem is a rich and mature environment with all sorts of programs and utilities that cover almost any situation, but back in the 1990s, printing support in Linux was fairly limited due to the large number of standards and protocols and the lack of Linux-specific drivers. In 1999, Easy Software Products saw this defect/opportunity and created the Common UNIX Printing System (CUPS). The CUPS solution basically turns the computer running it into a print server.

More importantly, CUPS provides a single standard that can handle many printers and protocols. CUPS was released in 1999 and was adopted by many Linux distributions. The CUPS printer service was quite successful for its time, but it could only support printers that had CUPS drivers, as well as the few printers with native support for Postscript.

In 2002, Apple was working on OS X, and, like every other operating system, it needed printing support. Apple decided to buy rather than build. Apple first licensed CUPS from Easy Software Products in 2002, but, after a few short years, they purchased the CUPS source code [3] and hired the lead developer Michael Sweet. CUPS is still used by Apple to support printing on all of their operating systems.

Apple owning CUPS might seem like a problem for the open source community, but that was not the case. Early Linux printing was difficult due to the number of different standards and protocols, but more importantly, Linux did not have a very large install base. Apple computers provided too large of a market segment to ignore, so printer companies started to provide printer drivers for Mac OS X. These drivers did not directly support Linux, but there was a great workaround. The workaround was to download the Mac driver and extract the PPD file and then test it to see if it worked for your specific printer. In many cases, this approach seemed to work. Since then, it has become much easier to find the PPD files for many popular printers [4].

No relationship is perfect, and the hundreds of improvements that Apple has committed to Git have slowed down to a trickle since 2020 [5]. CUPS was no longer progressing. The CUPS code was eventually forked and is now maintained by the Linux Foundation's OpenPrinting project, which serves as the upstream source for Apple's CUPS [6] .

Raspberry Pi Networking

One of the really forward-thinking design decisions built into CUPS is that it uses a web browser for the user interface (Figure 2). A browser interface makes it easier for CUPS to run on many different platforms big or small, and that means the Raspberry Pi is just as capable as a full-sized server.

Figure 2: Access CUPS through a web interface.

Coupling a DYMO label printer with a Raspberry Pi will make it a true network printer. I will also be able to add a queue to buffer if too many labels are printed at once. CUPS does all the hard work; it is just a matter of installing and configuring everything. Setup only takes a few minutes.

The first step might not even be necessary, depending on which Linux distribution you are using. It was not necessary to install CUPS on either Mint or on Raspberry Pi OS, but for a Debian-based distribution the command is:

sudo apt-get update && sudo apt-get install cups cups-client

If CUPS was not installed previously, you will also probably want to set up CUPS to start automatically when the system starts (see the sidebar entitled "In systemd"). Once CUPS is installed and the DYMO label printer is attached, you should verify that the operating system recognizes it. You can use the lsusb command to verify, or you can skip directly to the CUPS lpinfo command to display what devices are available. In my case, the lpinfo command displays both the DYMO LabelWriter 400 and my HP printer (Listing 1).

sudo systemctl enable cups

systemctl restart cups.service

systemctl stop cups.service
systemctl start cups.service

$ lpinfo -v
direct usb://DYMO/LabelWriter%20400?serial=07000619355405
file cups-brf:/
network beh
network ipp
direct vnc:/
network socket
network ipps
direct hp
network http
network lpd
network https
direct hpfax
network dnssd://HP%20Color%20LaserJet%20Pro%20M478f-9f%20%5BD7422C%5D._ipp._tcp.local/?uuid=b69de7ee-8055-5cc9-c1d0-526e9f44a5a5
network ipps://HP%20Color%20LaserJet%20Pro%20M478f-9f%20%5BD7422C%5D._ipps._tcp.local/
network socket://192.168.178.43:9100

You can install the DYMO printer while installing the CUPS software. But if you are feeling cautious, you can do each step separately.

sudo apt-get install printer-driver-dymo

This DYMO package does not actually add any drivers or programs but instead supplies a lot of defined page formats, which correspond to the labels that you can feed to the printer.

Configure the Printer

Setting up a DYMO printer from the CUPS menu (as shown in Figure 3) doesn't require very much user interaction. From the menu, click on the Administration menu and then click on the Add Printer button. This button will display a list of local and discovered printers; simply select the DYMO from the list.

Figure 3: List of local and discovered printers.

Clicking on the Continue button will bring up a dialog (Figure 4), allowing you to enter the name of the printer. Initially the printer queue name was DYMO_LabelWriter_400, which I shortened to DYMO_LW_400. This is just the local name that you can use to print to from the command prompt. During the setup, selecting the Share This Printer checkbox did not quite have the effect I was looking for (more on this later). Clicking on the Continue button will bring up another dialog (Figure 5), which allows you to select your printer model. These three dialogs are actually associating the printer that was found by CUPS with a user-provided name and model number.

Figure 4: Naming the queue and describing the printer.

Figure 5: Assigning the printer model of the previously named new printer.

Click on the Add Printer button to create the printer configuration and bring up a final dialog. This final dialog (Figure 6) defines a few settings, with the most important being the label size. My DYMO printer has an address label #99012, which is 89x36mm. This size seems a bit odd for a metric measurement but the size doesn't really look much better when converted to Imperial measurements: 3.5x1.4 inches. Pressing Set Default Options brings you back to the menu.

Figure 6: Setting printer defaults.

If you wish to verify that the printer was set up correctly, you can click on the Printers tab of the menu, but a more gratifying test would be to try to print a label. Use the lpstat command to see all available print queues (Listing 2).

pi@smartframe:~ $ lpstat -v
device for DYMO_LW_400: usb://DYMO/LabelWriter%20400?serial=07000619355405
device for HP_Color_LaserJet_Pro_M478f_9f_D7422C_: implicitclass://HP_Color_LaserJet_Pro_M478f_9f_D7422C_/

Initially, when I set up this printer, I was hoping that I could print out Internet postage from the German Post Office. It is possible to get a sample label from the German Post Office website [7], which does support the DYMO 99012 label as a PDF. I created a few test labels, which you can download from the Linux Magazine server [8].

The lp command lets me print a label on the newly defined DYMO_LW_400 printer queue from the command prompt:

lp -d DYMO_LW_400 testlabel.pdf

A more convenient testing method might be to create a document in LibreOffice (Figure 7). The first time I tried to print from LibreOffice, the page size was incorrect. To fix this problem, I selected Use Printer Properties and checked Use only paper size from printer preferences.

Figure 7: Printing from LibreOffice.

If the task was just setting up the printer locally, the process is complete. However, with just a few more small changes, you can make the printer available to the entire network. All of the configuration is in the cupsd.conf file, which is usually located in the /etc/cups directory.

CUPS listens only to the localhost on a port for print jobs but can be configured to accept jobs from the entire network. The configuration file has a line that defines a port number for listening on the network:

Listen localhost:631

This new configuration will listen on port 631 and essentially accept any IP address that can reach the printer server.

In addition to enabling network printing, it is possible to enable remote configuration and remote admin support. Each of these tasks has a block in the configuration file (Listing 3).

# Restrict access to the server to local network
<Location />
  Order allow,deny
  Allow from @LOCAL
</Location>

There are situations where allowing full access to the printer is inadvisable. In those cases, it is possible to limit access to a specific subnet. Adding a partial subnet will limit which computers can access the printer (Listing 4).

# Restrict access to the server...
<Location />
  Order allow,deny
  Allow from 192.168.178.*
</Location>

I planned to administer the printer remotely, so I added the "Allow from" statement to both the /admin and /admin/conf location blocks. Once I added these small changes, I had to restart the CUPS daemon. If there are any errors in the configuration file, the restart will not work and might display a cryptic message.

Once everything is correctly set up for your network and CUPS has restarted, you can use the lpstat -v command to see if your printer is visible to CUPS (Listing 5).

chris@chrismint20:~$ lpstat -v
device for DYMO_LabelWriter_400_smartframe: implicitclass://DYMO_LabelWriter_400_smartframe/
device for HP-HP-Color-LaserJet-Pro-M478f-9f-new: hp:/net/HP_Color_LaserJet_Pro_M478f-9f?hostname=HPBCE92FD7422C.local
device for HP_Color_LaserJet_Pro_M478f_9f_D7422C_: implicitclass://HP_Color_LaserJet_Pro_M478f_9f_D7422C_/
chris@chrismint20:~$

Direct Printing

When I first decided to use this label printer, it was with the goal of printing Internet postage from the German post office, but I also considered using it for creating and printing out address labels. I thought about writing a small program to print the labels but actually hoped someone might have solved this problem before me. Despite the number of DYMO projects on GitHub, I could not find one that solved my exact problem, even though there were quite a few DYMO label printer projects.

One interesting project [9] was short and contained a fairly concise example of printing complex labels. The label it produces was tailored by its author for a very specific case, but the code did help to illustrate the general Java programming techniques to output to a printer while using different fonts. The effort to create a Java program to print 5 or 6 line labels seemed a bit excessive, considering that I could easily use LibreOffice to create and print labels.