Label printers
Print QR labels for your bins, shelves, and parts so a scan takes you straight to a record. See QR labels for what the labels do. This page is the printer itself. Settle one question first, because it decides both what you buy and how you set it up: what holds the connection to the printer. There are three answers.
How the printer gets its jobs
- A print manager, over the network. The printer has a USB or network connection, CUPS drives it, and Cobblr hands CUPS a job. Anyone in the workspace can print, automations can print, and it works from any device including an iPhone. This is the route for a printer that lives on a desk or a shelf.
- Your browser, over Bluetooth. Small battery-powered label printers have no network connection at all, so Cobblr talks to them straight from the browser: Chrome or Edge on a desktop or Android device. Nothing to install and nothing to run, and the printer can travel with you. iPhones and iPads cannot do this. See Bluetooth label printers.
- An edge bridge, over Bluetooth. A small always-on machine near the printer (a Raspberry Pi being the usual choice) holds the Bluetooth connection and accepts jobs from Cobblr over the network. This is how a Bluetooth printer works from an iPhone, and how it prints when nobody is standing there, which is what an automation needs.
A direct-thermal printer needs no ink on any of these routes, which is what makes them cheap to run.
Route details: connecting, Bluetooth Classic, and the edge-bridge settings
On the browser route, connecting is a single Connect a printer step that finds the printer and fills its settings for you, and you are never asked to pick between kinds of Bluetooth. A printer that uses the older Bluetooth Classic, which no browser can reach over Bluetooth, is handled by pairing it in your computer first so Cobblr can reach it as a serial port.
The edge bridge is the same printer with the same settings. Only the route changes. You choose it by setting the printer's manager URL to Via edge bridge instead of Direct URL, picking the bridge from the list your workspace already knows, and letting it tell Cobblr which machines it serves rather than typing an instance name. A bridge running on the same computer you browse from is found automatically and prints straight from the browser with no token at all. This is the newest of the three routes, so treat it as the least proven for now.
What to buy
Two quite different kinds of printer make sense here, and which one suits you depends less on budget than on whether you want to carry it.
Portable Bluetooth printers, roughly $20 to $40
The category most people want for bins and parts: battery powered, pocket sized, and they travel with you, so you can label things where they stand.
- Most are the same hardware under many brand names: POLONO, NELKO and similar, usually as a "PM220" or a close variant. We bench-tested a POLONO PM220S and it works, and its settings ship with Cobblr.
- Anything in this class speaks TSPL, which is the dialect to pick when you add it.
- Phomemo M-series is the exception: those speak ESC/POS raster rather than TSPL. Picking the wrong one of the two is the single most common setup failure, and it looks exactly like a dead printer, so know which family you bought.
4 × 6 shipping-label printers
- Rollo, Brother QL, Zebra and Dymo all work, along with anything else CUPS can drive. These sit on a desk and connect over the network rather than Bluetooth, so they suit batch runs, automated printing, and printing from an iPhone.
- Already printing shipping labels? This costs you no new hardware. Cobblr tiles smaller labels onto a 4 × 6 sheet and you cut them apart with scissors, at whatever size suits the thing you are labeling, from 2 × 3 inch down to 1½ inch squares eight at a time.
- An adjustable paper guide skips the cutting: load a roll of die-cut 1½ inch or 2 inch squares, pick that size as your paper in Cobblr, and every label prints on its own ready to peel. Most of these printers take one.
Labels and rolls
- Die-cut or continuous. Die-cut labels come at a fixed size and print ready to peel, while continuous rolls you cut to length. Match the roll to the size you intend to print.
- Buy the size you actually want, in bulk, if you can. A 500 or 900 label roll of 1½ or 2 inch squares is the cheapest way to get small labels and involves no cutting.
- Check it fits. A pocket-sized Bluetooth printer has a pocket-sized compartment, and big rolls very often will not go in.
- Direct thermal needs no ink on any of these printers.
Roll economics, label fade, and where CUPS can run
When a big roll will not fit a portable printer, you end up buying smaller rolls at a worse price per label, or respooling the big ones yourself. This is the main argument for keeping a desk printer around if you label in volume, and using the portable one for walking around.
Thermal labels darken with heat, so they fade in sunlight over years. That is a non-issue on a bin in a workshop.
You do not need a dedicated print server for the CUPS route. It can run on the same box as Cobblr, on a Raspberry Pi, or on any machine on the network the printer is attached to.
Setup in short
For a Bluetooth printer, skip this and follow Bluetooth label printers instead. There is no CUPS involved. For a networked printer:
- Get the printer printing from CUPS first (add it in the CUPS admin, print a test page). This is a standard CUPS task, independent of Cobblr.
- In Cobblr, point Printing at that CUPS address and queue name.
- On a cloud install, a printer on your LAN is reached through the edge bridge, while a self-hosted install on the same network reaches it directly.
How the network route works underneath
Cobblr hands the print manager one finished job and tracks it. It never live-drives the printer, which is why any CUPS-supported model works without Cobblr knowing anything about it. CUPS is reached over IPP, and you configure a printer once with its address and queue name, and from then on any module or person prints to it with no per-user setup. See Printing for the connection steps.