I’m not entirely sure, but yet afraid this is default behavior and not configurable from within Firefox.

Try to find an option in the Mac system or printer settings - it should be there, but could be hard to find and may depend on the printer manufacturer. Perhaps this or this article can be of help?

@Tonnes Thanks, but those two links were more general issues with printing in black and white. I am having this problem SOLELY with Firefox. The print dialog box shows a check next to "Black and White," and the Presets show "Black and White," also.

Given that all other applications print in black and white when these are set, I don't think it's an issue with the printer or with the OS, except as they interact with Firefox. I circumvent the issue by saving the page as a pdf in the print dialog box, then printing from the pdf file. It's just getting to be a hassle.

My only other "fix," as it were, is to use another browser like Chrome or Safari. I am a creature of habit, though, and it annoys me that I can't stick with Firefox.

The links are general solutions allright since it can be a general issue on Mac as well as Linux (not to say it can’t be on Windows though). Firefox just does not send out grayscale print commands so you have to work around it, preferably in another way than via PDF. There is no user configurable option in Firefox other than the one for printing background colors, nor could I find an add-on that does the trick.

This question is about the same issue, offering a JavaScript method. And perhaps this method for creating a preset could be of help?

Btw, you don’t have to "leave" an entire program for such a tiny and probably resolvable issue. ;)

iMac running 10.10.5 Never had any printing issues with FFox until tonight. All of a sudden, the same exact procedure I use for printing grayscale from ANY website or doc did not work in FFox. Called Canon (my printer Pixma MG6320) support. We scoured troubleshooting ideas. Restarts, updated printer drivers. Tested grayscale with Safari & Chrome. Both successful. Random desktop files also printed grayscale. Updated FFox. No grayscale. Reinstalled FFox. Still no grayscale. It's FFox. For some undetermined reason, FFox all of a sudden stopped printing grayscale. My understanding is Mozilla has no working customer service phone. Appears the solution may only come through this forum or a site I have yet to discover. thanks for any feedback.

@smithl I have tried everything in the links suggested by Tonnes, above. I am running MacOS Sierra 10.12.2, and had this problem with Firefox even before updating to this OS. My printer is an Epson XP-310.

The problem is ONLY with Firefox, not with Chrome, Safari, nor any other app that I use. My only solution if I want to print from Firefox in black and white or grayscale is to click on Print, then save as a pdf file in the drop down in the lower left corner of the print dialog box. I then have to open the pdf file and print from there.

The upside to that work around, although it is a hassle, is that you can see exactly what will print on each page. Printing from Firefox, you don't get a print preview, and will sometimes get wasted pages.

I'm not a fan of Chrome or Safari, but why deal with an irritation that should be an easy fix for Mozilla?

@karenak I've seen other responses similar to yours which confirm this issue.

Another suggestion is to screen capture the image area and print that. It is another bugaboo that you cannot see a preview for appropriate scaling as you can in PDF printing and other sources.

I've wasted paper getting to the correct scale. With all the programming genius out there, can't understand why this option is not available in FFox print dialog box.

I rarely use Safari or Chrome as well. Not because I dont like them, but couple years back on 10.8 (not sure if that's the reason) I would get random gibberish with those browsers. Never did with FFox.

Since upgrade to 10.10, haven't seen it. But now have all my history trails and bookmarks in FFox. I googled forums out the kazoo looking for gibberish answers. Others had same issue, but no answers that worked.

In one forum, even a google team member intervened saying they did not know the solution either. And asked if anyone discovered it to enter it in the forum. I never went back.

@karenak Not sure why a sentence went randomly, partially italic. Strange. Did not click that button. And I can't correct it in the Edit this Post. It doesn't appear italic in the edit box.

@smithl Yes, I forgot to mention the screen capture option, which I also use frequently. As well, I have all my history, bookmarks, add-ons, etc. with FF.

Couldn't agree more with you about how these issues should be corrected quickly within the apps, given where we are technologically speaking. The other issue for me with Chrome is that the simplest procedures seem to have that many more steps/"click trails." And the occasional gibberish.

And now random italics in the support forum for FF...

When exactly did the issue start? Did it start after some Firefox update, some (Mac) OS update, or after doing something else that could affect current Firefox settings? Did it ever work properly anyway?

In order to find out if the issue is new to as well as caused by Firefox, you need to know it did work before, preferably when the issue started, and you could test by starting Firefox with a clean profile, which is fairly easy. If it turns out the issue started after a Firefox update, downgrading Firefox is the path to follow (at least to pinpoint the issue).

Did you also try some methods described on YouTube, such as here and here?

Sorry to sound impolite, but I wish you would read my original post (1.25.17 6:05 smithl) before responding. I covered all these issues in detail trying to save time and confusion. Please reread this post and get back to me. Don't want to explain it all over again. The links you supplied are simplistic instructions which I always use printing grayscale. thx

@smithl Sorry to sound impolite as well perhaps, but as you could have read when registering on this forum, you should have opened a separate question for your issue if you want to get help, even though it may sound a bit bureaucratic. Although your comments are valuated and can be of help to existing/reported issues, it is not my or anyone else’s task to carefully read them or other additions and help out with those. If not, issues as well as input by several people get mixed up and cause confusion. In other words, I was merely replying to the original poster only, which is the path to follow. Thanks for your understanding.

@karenak Unless my most recent questions above can shine a light on your issue or other helpers can verify nor confirm, this may be a more serious issue for which it may be best to file a bug in Bugzilla.

@Tonnes I indicated the date of my original post which should have made it easy to locate. I didn't enter a separate question because my search terms found this thread where others were already having same problem. I typically find that following these threads, often as not eventually someone will post a solution. Not yet so here. Why not accept that with so many posting same problem, not counting many who never bother posting queries but put up with the problem, this must be a FFox issue? Hopefully you are an exception. But I find many tech supports usually try to blame me or my computer for issues. We go through maze of ideas which never solve it only to realize it was on their end all along. Said they would file a report. They just didn't want to believe me to begin with. Posting once more my original comments in case it helps you solve it... original post: "1.25.17 6:05p iMac running 10.10.5 Never had any printing issues with FFox until tonight. All of a sudden, the same exact procedure I use for printing grayscale from ANY website or doc did not work in FFox. Called Canon (my printer Pixma MG6320) support. We scoured troubleshooting ideas. Restarts, updated printer drivers. Tested grayscale with Safari & Chrome. Both successful. Random desktop files also printed grayscale. Updated FFox. No grayscale. Reinstalled FFox. Still no grayscale. It's FFox. For some undetermined reason, FFox all of a sudden stopped printing grayscale. My understanding is Mozilla has no working customer service phone. Appears the solution may only come through this forum or a site I have yet to discover. thanks for any feedback."