Entire label doesn't print (intermittent)

Find Dennis' Gourmet Products on

Lite Finocchiaro

unread,

Feb 5, 2024, 3:10:19 PM2/5/24

to Dennis Reid, qz-print

Ok. So are you saying that all four times you got the same cutoff result? I would definitely suspect the printer or the driver, but if you're switching the (I'm guessing USB) cable from one PC to another on the fly, that could definitely be the source of your problems. At the very least I would power cycle the printer before connecting it to a different PC.

These label printers originally were designed to interpret raw printing commands for the most part (driverless), but what Amazon (and a lot of our other clients) is doing is leveraging the driver to send a graphical image (.png in your case). This is normally fine, but when you leverage the driver on a different PC, you can have different results. It's possible that the dimensions are different between your two computers, or that one is using landscape vs. portrait. There should be a another set of logs on the other laptop. If you want to send them my way, I'll be happy to have a look.

I appreciate the experience in troubleshooting, too, and we've heard stories from a lot of end users and sellers regarding Amazon support. I will say that Amazon has been responsive in the past when we've escalated to them, but I don't think your issue in particular is occurring because of something on their end. They provide the print data and config, and both look fine from what I've seen.

Can you tell me more about this Rollo density setting? Generally label printers only have one density, and it's 200, 300, or 600 dots per inch. You can't really change the print density without changing the print head. Printers that offer a higher density like 2400/1200 are usually oversampling the original density and saying it's 2x. There are also two dimensions to every print head, so you can have a different densities with respect to vertical and horizontal printing, but the printer specs will usually state this.

The Rollo/Logia/Vretti small footprint/form factor label printers that have exploded on the market lately, mostly thanks to Amazon in this part of the world, ironically, and people who have been working in label printing for a while are generally suspicious, because label printing always involved the same half-dozen or so major players, and all of a sudden there's twelve new manufacturers, and each one only sells on printer (or two, of which one is USB and the other is Bluetooth), and they all look exactly the same...

We've tested on Logia locally with no issues, but we only print for the sake of testing. In a production environment, the stakes are higher and tolerances are lower.

Cheers,

Lite

Tres Finocchiaro

unread,

Feb 6, 2024, 10:39:56 AM2/6/24

to Lite Finocchiaro, Dennis Reid, qz-print

Perhaps try to reproduce on our demo page?

https://demo.qz.io

You can even drag-and-drop the image file from Amazon.

Dennis Reid

unread,

Feb 6, 2024, 10:45:19 AM2/6/24

to Tres Finocchiaro, Lite Finocchiaro, qz-print

Interesting. I will try that, thank you.

BTW - I opened a case with Amazon. The said that it looked like the issue was resolved and closed the case. I reopened it and asked them to read the issue description and support request I wrote. Frankly, this was the answer I expected from them…

Dennis G. Reid

Vice President

Reva Foods, LLC

Find Dennis' Gourmet Products on

Tres Finocchiaro

unread,

Feb 6, 2024, 11:43:31 AM2/6/24

to Dennis Reid, Lite Finocchiaro, qz-print

Dennis,

Sorry for the lack of support on Amazon's side.

I spoke with Lite today about your issue and I think we can help exhaust any problems with the QZ Tray software as long as you're willing to do some trial and error with us, which your original email seems to already do quite a bit of.

In short, there should be no reason that QZ Tray would cause a printer to print partials. There are some baseline testing that can be done to help narrow this down:

Instead of printing to the Rollo, print to a virtual printer (e.g. Microsoft Print to PDF, etc). If that reproduces the issue, QZ Tray may be at fault.
Instead of using Amazon's website, attempt to print through our demo page. If needed, we can probably extract and send you the Amazon Label so that you can drag and drop this file. I understand that if the problem is intermittent, some things may appear to help -- such as print density (I assume this is a darkness setting?) -- but then the problem will come back. We're not aware of any darkness settings contributing to print failures in any of the hardware we've ever tested against.
I understand other software (e.g. Acrobat) doesn't suffer the same problem. This is good information to know. If this problem only occurs with QZ Tray and Rollo, it may be a bug with the printer firmware, but isolating this would require coordination with Rollo engineers.

If needed, we can buy an identical Rollo as well to see if this problem is reproducible on our end. This would drastically speed up escalation with Rollo.

Hopefully this response helps explain our dedication to making QZ Tray the best it can be. We do normally ask that users escalate issues to the website or hardware providers, but most users don't perform their own troubleshooting as you have, so we would consider your case a good candidate for direct help. :)

- Tres.Fin...@gmail.com

Dennis Reid

unread,

Feb 6, 2024, 12:36:32 PM2/6/24

to Tres Finocchiaro, Lite Finocchiaro, qz-print

Hi Tres,

These are all very good ideas.

I went back to every order we processed yesterday and printed each label to MS Print to PDF. All labels, including the one that we had the issue with, printed correctly. I will attempt to print the labels from your demo page next.

Your description of how the issue occurs is correct. We print labels two ways; Amazon/QZ Tray and directly printing PDFs with Acrobat. Amazon/QZ Tray is the only one with this issue. I agree with your premise that QZ Tray should not be the root cause. I also agree with your premise that it could be in the printer firmware.

As far as density, yes - that sets the darkness of the print with 0 being the latest and 15 being the darkest. Rollo does warn to be careful not to set the density too high as it could print too hot and the print operation could just stop in the middle of printing, which is not our issue. I've never printed anything above a 4. As I previously mentioned, when we have the issue, I reduce the density until either the prints work or it's too light. For the latter, I use the other laptop and it prints successfully.

Another piece of the puzzle is that the Rollo has a distinct sound when it prints. The sound is markedly different at the start of the print when it's about to print a partial label. It sounds like it's printing but the label is not moving. Back in the 70's, I was a computer operator and I could tell when printers were having problems by the sounds they made.

Anyway, I'm wondering if it's printing the 1st third of the label on one line at the top of the page (see image previously provided). There's a line at the top of the page, just above the QR code, that appears to be one dark line and another, more faint line right below it. When printed properly the line above the QR code is a solid thin line. This is another reason why I'm leaning toward a printer issue.

I'll update you again when I've tried your demo site.

Regards,

Dennis

Dennis G. Reid

Vice President

Reva Foods, LLC

Find Dennis' Gourmet Products on

Tres Finocchiaro

unread,

Feb 6, 2024, 12:42:02 PM2/6/24

to Dennis Reid, Lite Finocchiaro, qz-print

I was a computer operator for several years, I know what you're talking about. If we can make this problem reproducible without Amazon in the picture that will help for sure.

In regards to what's different about QZ Tray, there are some cases where we've seen misbehaving printer drivers. For example, some Brother printers would misbehave unless we explicitly configured certain settings in the preferences pane of the driver. We use Java to print, so there's always a chance that applications like Adobe are talking to Winspool slightly differently than Java is. This gets pretty low-level in the driver comms (and it's mostly Java code) so we always hope that we can find a workaround, as fixing a bug deep in the Java language generally takes months. :)

Dennis Reid

unread,

Feb 6, 2024, 12:50:51 PM2/6/24

to Tres Finocchiaro, Lite Finocchiaro, qz-print

OK, I'm on the demo page but I've no idea if I'm doing it correctly. The page found my printer and I uploaded the label PDF and then clicked on the green "Print dropped" button. I clicked allow for "localhost want to print to Rollo Printer" Nothing has happened.

Dennis G. Reid

Vice President

Reva Foods, LLC

Find Dennis' Gourmet Products on

Tres Finocchiaro

unread,

Feb 6, 2024, 12:53:15 PM2/6/24

to Dennis Reid, Lite Finocchiaro, qz-print

Sorry, can you click the "Pixel" tab and try again? That EPL format is proprietary and for older Zebra printers only.

Dennis Reid

unread,

Feb 6, 2024, 1:03:45 PM2/6/24

to Tres Finocchiaro, Lite Finocchiaro, qz-print

OK, I tried Pixel. I click on "upload file", the file selection dialog box appears and I select the label pdf and click open. It acknowledges the open but nothing happens. I would assume the "upload file" will change to the green button again like on the EPL tab.

I did click on the "print PDF" button and that printed a page. I attached an image of it.

Dennis G. Reid

Vice President

Reva Foods, LLC

Find Dennis' Gourmet Products on

test pdf label.jpg

Dennis Reid

unread,

Feb 6, 2024, 1:06:47 PM2/6/24

to Tres Finocchiaro, Lite Finocchiaro, qz-print

OK so here's something interesting. The 1st PDF I attempted to print was the one that had issues previously. I chose one of the other files and it printed. The print isn't to scale because I didn't set any parameters but it printed.

These PDFs are the one that came from MS Print to PDF

Dennis G. Reid

Vice President

Reva Foods, LLC

Find Dennis' Gourmet Products on

Dennis Reid

unread,

Feb 6, 2024, 3:18:15 PM2/6/24

to Lite Finocchiaro, qz-print

Hi Lite,

I'm saying that 3 of the 4 times, the issue occurred and they all looked like the image I provided. The 4th time, I disconnected the cable from one laptop, connected it to the other, and the label printed correctly. I did not power cycle the printer. I wonder if power cycling the printer while attached to the same laptop will make a difference. I'll have to try that.

I understand your point on power cycling but do the switch frequently. Normally, the printer is not connected to any laptop and is plugged in only when we need to print a label. I think that with plug and play, this shouldn't be as much of an issue as it was 10 years ago. Again, the ONLY time this issue occurs is within Amazon shipping. We do a fair amount on stamps.com, which simply generates a PDF and we print from Acrobat.

I've not had the time to check all of the settings on both laptops but I'll do that later once my wife is finished with her work.

I can see that Amazon support would be better for you as a critical vendor. I have many horror stories but my favorite is when they changed 5 out of 9 of my salsa listings from the salsa category to dietary supplements and told me I had to reapply to sell. I lost 6 weeks of sales with that one.

All I can tell you is that on the printer preferences, I can set density anywhere from 0 - 15. The Rollo printer has been ok but when I have these issues, it brings us to a standstill. This stuff isn't rocket science and it should just work.

I've included the QZ logs from my laptop but I haven't had to print in a while and I haven't had the issue for some time.

Lastly, can you name some of the major players for thermal printers? I'd like to research them and maybe replace the printer - hopefully with something wireless.

Thanks,

Dennis

Dennis G. Reid

Vice President

Reva Foods, LLC