Affected versions

• 81.0b7
• 82.0a1 (2020-09-08)

Affected platforms

• Windows 7

Steps to reproduce

1. Launch Firefox
2. Make sure print.tab_modal.enabled is set on true
3. Open any page
4. Destination is set on a connected printer

Expected result

• The content is not blurry

Actual result

• The content is blurry

Regression range

• Pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=432e42cbbc4139efd2319952ec33efe8ff9add3c&tochange=369f72130f3604c85f73a3b03b2b48f33ad9b19e

Additional notes

• The issue is not reproducible with other option from Destination

Suggested severity

• S3 since affects only win 7

I can reproduce this issue with the old ui as well with the steps bellow:

1. Make sure print.tab_modal.enabled is set on false
2. Open any page
3. Open the page in print preview
4. Print it to paper
5. Still in Print preview, change the scale (more visible if set under 100%) or/and Orientation

On the old UI I ended up with the following regression; not sure if the previous one checked for the new ui is valid - I will double check it soon:

• Last good revision: 6a146cf8deb2d3a863f4a54cd2de77cb36b7de6f
• First bad revision: 07523f6e83410bf3ae73fc69184ca9ebd28139d7
• Pushlog:
  https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=6a146cf8deb2d
  3a863f4a54cd2de77cb36b7de6f&tochange=07523f6e83410bf3ae73fc69184ca9ebd28139d7

Looks like bug Bug 1660986 could be the culprit here

• Manage to see this issue with the old UI , as well, only on Windows 7

Changing to [old-ui+] given comment 1.

Hey Glen, is this possibly something with painting related to changes in the parent?

I'm not sure what you mean by that question - could you provide more context?

Do we know if this is WebRender specific and/or occurs with WR disabled?

Anca, is this still an issue? jfkthame bumped the default resolution in bug 1662820 (although we should maybe consider bumping it further).

(In reply to Jonathan Watt [:jwatt] from comment #5)

Anca, is this still an issue? jfkthame bumped the default resolution in bug 1662820 (although we should maybe consider bumping it further).

Yes, this is still an issue on my side, the print preview is blurry, tested with 83.0a1 (2020-09-30) and 82.0b5 on Windows 7.

Thanks. Can you see whether temporarily setting the pref print.default_dpi (a string pref) to "300.0", or even "600.0" improves things at all for you?

Apparently this issue is visible on Ubuntu 18.04 using the same test machine (my colleagues didn't ran into this issue); the network printer used is Kyocera ECOSYS P2135dn

(In reply to Jonathan Watt [:jwatt] from comment #7)

Thanks. Can you see whether temporarily setting the pref print.default_dpi (a string pref) to "300.0", or even "600.0" improves things at all for you?

I don't see any improvements by changing the pref value

Anca, thanks for the about:support. Can you use a Nightly build to get the about:support though, since it will include additional useful information? Also, if you can use the "Copy text to clipboard" button (instead of "Copy raw data to clipboard") that would be appreciated.

Also, presumably the preview is only blurry if 'Black and White' is selected. If you were able to switch to 'Color' (can you now, in the latest Nightly/Beta?) I suppose things are fine?

(In reply to Jonathan Watt [:jwatt] from comment #11)

Also, presumably the preview is only blurry if 'Black and White' is selected. If you were able to switch to 'Color' (can you now, in the latest Nightly/Beta?) I suppose things are fine?

Yes, you are right, when set to Color the preview looks good.

If you set gfx.webrender.force-disabled = true and restart the browser, are things still blurry?

(In reply to Jonathan Watt [:jwatt] from comment #14)

If you set gfx.webrender.force-disabled = true and restart the browser, are things still blurry?

Yes, the content is still blurry.

I can reproduce this in Windows 10 x64, v85.0. Either "Save to PDF", "Microsoft Print to PDF" or my actual Printer, everything is blurry. Setting "print.default_dpi" from 144 to 600 fixes the issue, even if all the config strings of each printer mode are set to 600.

Firefox for Windows to printer: Affected
FF Linux to PDF -> External PDF reader on Windows: Unaffected
FF Linux to PDF -> FF Windows to printer: Affected

I think this needs to be addressed ASAP, I've almost ditched FF as I've been wasting a TON of paper and toner! Issues like this passing versions without actual fixes are what break users' confidence.

Nevermind, this bug is about the preview and I can't delete nor edit my former comment.