Small and inexpensive direct thermal printer to print labels

[Corporate666]

I am working on an industrial device that I would like to be able to print out direct thermally printed labels for part identification at the time of manufacture.

I have seen little receipt printers that can be interfaced with Arduino's and such, but wondering if anyone has experience with something that can be used for labels and is relatively easy to interface with and which can be incorporated as part of a larger device (ideally).

I mean something around the size of a pack of cigarettes that I can talk to via serial would be ideal.

[aliarifat794]

You can take a look at Zebra LP 2824 Plus.

[abeyer]

I don't know of anything intended to be integrated into another product... though would be interested to see if you find something. Also, I think you can do labels in many of the "receipt" printers if you find label rolls the right size, and that narrow width works for what you need.

If you go with an off the shelf product and just do the integration, Zebra as mentioned, or Brother would be where I'd look.

[Wilson__]

Small size, will be thermal printer.  Some use 'normal thermal paper' that fade over time.  There are high grade thermal paper that do not fade for a few years.

Larger size you can have thermal transfer printer that transfer ink from ribbon onto the printout and permanent.  hope this help

[ajb]

Also, I think you can do labels in many of the "receipt" printers if you find label rolls the right size, and that narrow width works for what you need.

You can probably print onto a label roll, but you won't be able to align the printing to the labels unless the printer is designed for label printing.  Since the print head has to be some distance inside the printer housing, the printer has to advance the last label past the print head to the tearoff point, and then it has to retract the roll back to the print head before printing the next label.  Printers designed for labels will have sensors to detect the web between labels or marks on the roll for this purpose. 

[thm_w]

Need more information on this "industrial device" is it a computer? Running linux or custom OS?
Can it supply enough power at 12V directly to the printer (5-20W+)?

USB usually is probably easier unless it is a lower spec device.

[artag]

I believe the brother label printers (usually USB, thermal, a wide variety of cheap clone labels available) are supported by drivers within the CUPS printer control system in Linux.

Receipt printers intended for integration in POS terminals used to be primarily from Epson and had parallel or serial interfaces. These may be more suitable if you have a simpler embedded system and don't want to run Linux - though it has many advantages such as easy ability to support remote login, web control pages etc. If the core functions are very simple it might be sensible to implement those on a microcontroller and then put peripheral functions such as web control and printing on a small embedded linux board that isn't essential for basic operation.

[tooki]

I believe the brother label printers (usually USB, thermal, a wide variety of cheap clone labels available) are supported by drivers within the CUPS printer control system in Linux.

They probably are, but for inventory labels like this, where it’s likely that bar codes are involved, you don’t want to print using regular OS print drivers, you instead want to use the printer’s own command language to ensure that bar codes are printed perfectly sharp.

Receipt printers intended for integration in POS terminals used to be primarily from Epson and had parallel or serial interfaces.

Epson and Star Micronics are the two heavyweights in that market.

[tooki]

I am working on an industrial device that I would like to be able to print out direct thermally printed labels for part identification at the time of manufacture.

I have seen little receipt printers that can be interfaced with Arduino's and such, but wondering if anyone has experience with something that can be used for labels and is relatively easy to interface with and which can be incorporated as part of a larger device (ideally).

I mean something around the size of a pack of cigarettes that I can talk to via serial would be ideal.

You don’t specify what manufacturing volume you’re dealing with, but as a general rule, using el-cheapo borderline-toy products (which is what those Arduino products are) is not something I’d want to risk my production schedules to.

You want a proper label printer. You don’t specify whether you want to simply hide an off-the-shelf printer inside your device (the way that most self-checkout machines actually just use an ordinary, unmodified receipt printer inside, just with the exit slot facing through the cabinet), or truly integrated, like the baggage tag printers on airport self-checkin kiosks, or even one that automatically applies the label to the product. The former is easy, the second a bit tougher because you may face minimum order quantities for bare mechanisms, the third a lot harder.

Many companies sell OEM printer mechanisms; you really should start with a google search for “OEM label printer mechanism”. You’ll be surprised how much you find. Your best bet is probably not to deal with the manufacturer itself, but with one of the many system integrators who specialize in customizing them.

But before you contact them, nail down your requirements:
- print volume (labels per minute/hour for print speed requirements, and labels per month/year for reliability requirements)
- label size(s)
- what is the substrate your labels (or direct printing) will go on?
- label durability (environmental (temp, humidity, sunlight), chemical (solvents/oils/liquids, etc), mechanical (abrasion resistance, adhesion, etc), longevity (does if need to be legible for a year? Five? Thirty?)). This will inform the printing technology you need (thermal, thermal transfer, inkjet labels, inkjet directly onto the item or packaging), the label material (paper, plastic film), lamination, etc.
- with or without liner
- label contents: text, bar codes, images? Black and white, two color, or full color?
- print resolution, depending on your application
- label data variability: does each label’s content vary individually (e.g. for serial numbers) or is it static (e.g. date or lot codes that only vary once per job)? (For truly unchanging data like just model numbers, preprinted stickers would probably be cheaper in the long run.)
- interface requirements: what hardware is driving it, so what hardware interface do you have? Serial (UART, RS232, RS485), industrial bus (MODBUS or whatever), parallel port, USB, Ethernet? And what software will drive it?
- level of automation (from full manual, all the way to automatically applying labels unattended; cut labels? Endless?)
- any applicable regulatory requirements (for example, food packaging has to use food-save inks).
- printer downtime (is production affected by having to take the printer offline to refill, clean, or repair it? Or do you need two for redundancy?)

And that’s just what I can think of off the top of my head. Think about these things so that you can answer whatever questions the integrator asks.

[Perkele]

These guys had reasonably priced printers when I was using them:
https://www.custom.biz/en_GB/product/hardware/printers/kiosk-receipt-printers/kpm180h

Most of them use ESC/POS or some kind of "binary" comms protocols.
ESC/POS is supported on multiple platforms, would not be surprised if someone also did an Arduino library for it.

[tooki]

These guys had reasonably priced printers when I was using them:
https://www.custom.biz/en_GB/product/hardware/printers/kiosk-receipt-printers/kpm180h

Out of curiosity: what are their ordering requirements like? (Generally speaking, when I see a website that doesn’t list any prices, nor even a network of distributors, I tend to assume they want nothing to do with you if you’re not going to buy hundreds of units or more.)

Most of them use ESC/POS or some kind of "binary" comms protocols.
ESC/POS is supported on multiple platforms, would not be surprised if someone also did an Arduino library for it.

There are several.

[ajb]

I believe the brother label printers (usually USB, thermal, a wide variety of cheap clone labels available) are supported by drivers within the CUPS printer control system in Linux.

They probably are, but for inventory labels like this, where it’s likely that bar codes are involved, you don’t want to print using regular OS print drivers, you instead want to use the printer’s own command language to ensure that bar codes are printed perfectly sharp.

Well, you *can* do decent barcodes via OS print drivers, but it requires some careful management of the print data to get good results.  Any raster content sent to the printer, especially barcodes, should exactly match the printer's native resolution, and should be uncompressed 1-bit monochrome.  Whether it's worth dealing with that versus dealing with ZPL or whatever will depend on the application. 

Source: I got fed up with Brady's shitty label printing software and stupidly limited printer command languages, so I built my own HTML template -> raster image -> Windows print API pipeline.  I had to jump through a couple hoops to correctly scale the template content to match the print resolution, and manually collapse the color space to 1-bit to eliminate any image compression artifacts, but everything comes out nice and crisp, even with relatively tight linear barcodes.  (Modern camera-based barcode scanners also help, since the image processing has to correct for a lot of other confounding factors anyway.)

[tooki]

I believe the brother label printers (usually USB, thermal, a wide variety of cheap clone labels available) are supported by drivers within the CUPS printer control system in Linux.

They probably are, but for inventory labels like this, where it’s likely that bar codes are involved, you don’t want to print using regular OS print drivers, you instead want to use the printer’s own command language to ensure that bar codes are printed perfectly sharp.

Well, you *can* do decent barcodes via OS print drivers, but it requires some careful management of the print data to get good results.  Any raster content sent to the printer, especially barcodes, should exactly match the printer's native resolution, and should be uncompressed 1-bit monochrome.  Whether it's worth dealing with that versus dealing with ZPL or whatever will depend on the application. 

Source: I got fed up with Brady's shitty label printing software and stupidly limited printer command languages, so I built my own HTML template -> raster image -> Windows print API pipeline.  I had to jump through a couple hoops to correctly scale the template content to match the print resolution, and manually collapse the color space to 1-bit to eliminate any image compression artifacts, but everything comes out nice and crisp, even with relatively tight linear barcodes.  (Modern camera-based barcode scanners also help, since the image processing has to correct for a lot of other confounding factors anyway.)

Exactly. That effort is precisely why I said you don’t want to use the OS printing (not that it’s categorically impossible to get good results using it*). Using printer commands (ZPL, ESC/POS, etc) ensures you get clean results.

You’re definitely right about camera-based scanning. Even blurry bar codes seem to scan well. Heck, I find it almost annoying (on principle alone, as a perfectionist) that my bank’s 2D bar code scanning (for 2-factor authentication, and for scanning bills) recognizes codes before the camera has even finished focusing on it! I’ve also had no trouble scanning bar codes in PDFs where the bar code is stupidly saved as a bitmap image, which a lot of software will then apply an interpolation filter to when scaling for printing, resulting in blur. (It’s definitely better to have it as a vector “font” or vector graphics, so that it always prints sharp.)

*I worked at the Apple Store many years ago, and their receipt printers use OS printing so that it can print in the corporate font instead of the printer’s ROM fonts. They had clearly worked out how to get clean bar codes, of course. But the text is actually not great, you can tell the font is not optimized for low resolution. As far as I can tell, their POS system still works that way to this day.