Hi Derek, some possible issues might be:

(1) Scaling set to a fixed percentage (instead of Fit to page width)

(2) Crazy margins

(3) Firefox stored the wrong paper size for the printer

For #1, it's easy for you to check. If that causes the print to shrink within the upper left corner, then we should investigate #2 and #3.

(A) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(B) In the search box in the page, type or paste print_margin and pause while the list is filtered

Firefox should display top, left, right, and bottom margins for all of the printers you have used. If you are using inch measurements, the values typically would be in the range of 0.2 to 0.5 (often with numerous additional digits).

(C) If you need to fix a value, double-click that row to display an editing field, and change the value to 0.5 or whatever you like, then press Enter or click the blue check mark button to save the change.

(D) In the search box in the page, type or paste print_edge and pause while the list is filtered

Firefox should display top, left, right, and bottom "unprintable area" values for all of the printers you have used. This typically would be a number between 0 and 20 (20 is 0.2 inches).

(E) If you need to fix a value, double-click that row to display an editing field, and change the value to 20 or whatever you like, then press Enter or click the blue check mark button to save the change.

(F) In the search box in the page, type or paste paper_id and pause while the list is filtered

Firefox should display a value for every printer. This number can vary a lot, but some common ones are:

• 1 => letter size (8.5 x 11)
• 9 => A4 size

(G) If you need to fix a value, double-click that row to display an editing field, and change the value to 1 or whatever you like, then press Enter or click the blue check mark button to save the change.

Any improvement so far?

Thanks so much for your thorough reply. Unfortunately, the tips didn't address the problem. I had already verified those values in both the FF print dialog and system print dialog but I went through your suggested about:config values to make sure something wasn't wonky and they were correct as you had noted.

Being as how the print was working as normal on my computer yesterday without issue and is exhibiting the same issues on a totally different workstation and account, only after version update, I really think it has to do with the current version of Firefox, 90.0 64-bit according to my About menu, and how it's reading that site. I'm not sure if I'm able to post external links but have you tried printing from the page in the screenshot (per the address in the header) to see if you're having the same issue? All product pages seem to be doing it.

Thanks, Derek

Hi Derek, I see the problem now. The Preview (first screenshot) looks perfect but the actual output (second screenshot) is missing various content. Very strange.

If I adjust the scaling for a better fit (preview/actual attached), the identical text is visible, suggesting that this is not related to a margin, but some characteristic of the page layout that is flummoxing Firefox.

I don't have a good theory about what is going on here.

A typical method of tracking down the source of the problem is to try numerous versions of Firefox between Firefox 89 and Firefox 90 until you figure out exactly what changed. This is a bit time-consuming, so probably not a project either of us can undertake immediately. Let's see what we learn in other threads today. For future reference, this involves a tool named Mozregression: https://mozilla.github.io/mozregression/.

Yep, I was thinking the same. I've seen it on a few other site pages I've printed, more backend stuff which I can't share, so hopefully it's addressed soon. I think if I were to roll back to a previous version, it would work but I'll probably just use Chrome until it's addressed.

Thanks again for your help and input!

Derek

I cross-posted the issue to the r/Firefox subreddit to see whether anyone there recognizes this.

https://www.reddit.com/r/firefox/comments/okdogl/fx90_scaled_printouts_missing_content/

Thanks so much for your thorough reply. Unfortunately, the tips didn't address the problem. I had already verified those values in both the FF print dialog and system print dialog but I went through your suggested about:config values to make sure something wasn't wonky and they were correct as you had noted. Being as how the print was working as normal on my computer yesterday without issue and is exhibiting the same issues on a totally different workstation and account, only after version update, I really think it has to do with the current version of Firefox, 90.0 64-bit according to my About menu, and how it's reading that site. I'm not sure if I'm able to post external links but have you tried printing from the page in the screenshot (per the address in the header) to see if you're having the same issue? All product pages seem to be doing it. Thanks, Derek

Yes i do have same issue for thermal printing

Two of us filed bug reports tonight. Hopefully it can be addressed in an emergency fix so we don't have to wait for Firefox 91 -- this is not acceptable for anyone who needs to print for their work.

• https://bugzilla.mozilla.org/show_bug.cgi?id=1720621
• https://bugzilla.mozilla.org/show_bug.cgi?id=1720622

Same here. I've duplicated the error on three different PCs, all using Firefox 90.

I print numerous reports that need to be scaled to 50% and printed landscape on legal paper. As soon as the reduction drops below 94% I do not get complete reports. I've switched to Chrome for printing.

On a side note, I see that the word wrap flag has been reinstated in the config file! Yay! No more CTRL-U to get a printable report.

I wrote a script as a potential workaround, which you can run on a page using a bookmarklet (script saved as a bookmark). Here's a brief rundown of how it works:

(1) Check the preview to detect the scaling problem. For example, on https://www.jeffersonscher.com/res/widepage.html --

(2) If you don't have the script, install from https://www.jeffersonscher.com/res/sumomarklets.html#scale4print Drag the button to a convenient location --

(3) Click the bookmark and enter a scaling percentage then click OK. The script will suggest something based on the width of the document body, but it's just a starting point.

(4) Check the preview again. If that was enough, go ahead and print. If it's not right, cancel the preview and click the button again to enter a revised value.

To remove the scaling from the page, click the bookmark one more time and click Cancel.

Reverting to the previous FF version fixes the problem. FF90 besides the page truncation, does not retain the last target printer used, and also appears to not properly load all the printer attributes correctly.

Reverting to the previous FF version fixes the problem. FF90 besides the page truncation, does not retain the last target printer used, and also appears to not properly load all the printer attributes correctly.

Firefox 89 did not have the scaling bug. However, older versions are not a recommended workaround. See: Install an older version of Firefox.

I have not experienced any problems with Firefox 90 remembering my last-used printer. Please start a new thread about the problem with printer attributes so we can know more about what you mean.

To start a new thread: https://support.mozilla.org/questions/new/desktop/form

A Firefox update (Firefox 90.0.2) has been released to fix this printing bug in Firefox 90. Release notes: https://www.mozilla.org/en-US/firefox/90.0.2/releasenotes/ (quote) Fixed truncated output when printing (bug 1720621)

I've verified that this has fixed the issue for me.

Thanks, Derek