"Two-sided" is configured per-profile and not enabled by default on fresh chrome, however if user enabled it on any printer, it becomes enabled for all printers across the profile. (isDuplexEnabled: true|false in Preferences file).

Would be good to have a policy, per use case above.

Technical case opened in the support platform, the user states users in the organization started getting the "two-sided" printing option enabled by default starting today.  This is impacting the printer behavior.  

There's a request to either enable a policy to manage this feature or to revert to previous behavior.   Able to reproduce on my testing environment.  Chrome OS 69.0.3497.120

Confirm this on chromeOS,  69.0.3497.120
Changing type to Bug-regression and adding proper components

I am guessing this is caused by the change to the new Print Preview. Can you confirm by disabling "New Print Preview" in chrome://flags? We can disable the flag in Finch for M69 on Chrome OS if this fixes the issue, and then try to merge a fix back to 71 and, if possible, 70.

I have a possible fix, but need access to a printer that does not enable duplex by default to confirm. Every printer I have tried so far enables duplex by default regardless of the state of the new print preview flag. cardomam@, is there any chance you can share a printer that you have been able to reproduce the issue with?

Addition to comment 5: If you cannot share the printer, I can also land a speculative fix that you can test in Canary.

Adding Needs-Feedback. In order to confirm the cause, since I can't reproduce this issue locally, I need someone who can reproduce to:
(1) Verify that it is fixed if the "New Print Preview" flag is disabled (if this doesn't fix the issue, it is being caused by something else).
(2) If possible, share a printer for which Print Preview displays the (checked) duplex checkbox that does not support duplex printing. So far, every printer I have tried either doesn't cause Print Preview to display the checkbox, or actually supports duplex printing.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b0f2b8367cee08dee6f6f7c62c56c7e462877ca1

commit b0f2b8367cee08dee6f6f7c62c56c7e462877ca1
Author: rbpotter <rbpotter@chromium.org>
Date: Tue Oct 23 00:03:25 2018

Print Preview: Fix duplex defaults

Check the internals of the duplex capability, instead of only checking
for its existence, to determine whether to display the duplex checkbox.
Pull default value from the printer if it is available.

Currently a speculative fix, as have not been able to identify a
printer which sets the duplex capability field but does not actually
support duplex.

Bug: 896244
Change-Id: Iebafc3878a1e7658b821465439ee172c479ce413
Reviewed-on: https://chromium-review.googlesource.com/c/1290145
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#601790}
[modify] https://crrev.com/b0f2b8367cee08dee6f6f7c62c56c7e462877ca1/chrome/browser/resources/print_preview/new/model.js
[modify] https://crrev.com/b0f2b8367cee08dee6f6f7c62c56c7e462877ca1/chrome/test/data/webui/print_preview/settings_section_test.js

Landed a speculative fix in Canary which should be available in version  72.0.3589.0. Can someone who can reproduce this issue test and see if it is fixed there?

cc-ing cardonam@ who indicated in comment 2 that they may have a way to reproduce this. See questions in comments 8 and 10.

 Issue 898582  has been merged into this issue.

Found a report from the product forum.  More details in the dup'd bug.
https://productforums.google.com/forum/?utm_medium=email&utm_source=footer#!msg/chrome/JwObYaN69ic/K-bDCuDyBQAJ

Thank you for the update.  

I updated a Pixelbook to Canary v72.0.3589.0.  Tested in both duplex capable and not capable printers, Enable Print Preview bot enabled and disabled.  The "two-sided" option shows unchecked by default.  

Tested in Chrome browser Dev version in Mac as well.  Same results.

Tested in v69 (Chrome OS and Browser in Mac) and it's still showing up checked by default so the fix seems to be working as mentioned in comment 10.

All tests were completed using the same 3 user accounts from different domains.

Comment 15: thanks for confirming.

I was eventually able to reproduce the incorrect default setting on Windows 10 with an HP LaserJet driver. Was then able to confirm it does not reproduce if the new print preview flag is disabled, and that it is fixed by the patch in comment 9 on Chrome Canary 72.0.3589.0.

Requesting a merge to M-71 for the fix in comment 9, which also includes a new automated test.

Will land a finch change later today to turn the flag off for M69 and M70, which should fix the issue for everyone currently impacted.

Adding label, see comment above.

From comment 15.   *Both Chrome OS and Mac browser versions tested on Canary (v72).

This bug requires manual review: M71 has already been promoted to the beta branch, so this requires manual review
Please contact the milestone owner if you have questions.
Owners: benmason@(Android), kariahda@(iOS), kbleicher@(ChromeOS), govind@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

As this is regressed in M69, how critical it is to merge to M71 Beta and how safe it is?

This regressed in 69 only after the new print preview flag was turned on. We can roll the flag back for 69 and 70 to prevent the regression from impacting those milestones, and I have a finch CL out for review to do this currently. However, for 71, this is on by default on ToT, so it is critical to merge to 71 Beta to prevent the regression from coming back in M71. If we don't merge this we would need to merge a different change to flip the flag back.

The change is verified by automated tests, is relatively small and impacts only one area of code, and has been verified on Canary by both myself and cardonam@, so it should be a safe change to merge.

Approving merge to M71 branch 3578 based on comment #21. Pls merge ASAP. Thank you.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/c94e97dc36eecf3413b1e22d3782844750bdf04e

commit c94e97dc36eecf3413b1e22d3782844750bdf04e
Author: rbpotter <rbpotter@chromium.org>
Date: Thu Oct 25 18:50:32 2018

Print Preview: Fix duplex defaults (M71)

Check the internals of the duplex capability, instead of only checking
for its existence, to determine whether to display the duplex checkbox.
Pull default value from the printer if it is available.

Currently a speculative fix, as have not been able to identify a
printer which sets the duplex capability field but does not actually
support duplex.

Bug: 896244
Change-Id: Iebafc3878a1e7658b821465439ee172c479ce413
Reviewed-on: https://chromium-review.googlesource.com/c/1290145
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#601790}(cherry picked from commit b0f2b8367cee08dee6f6f7c62c56c7e462877ca1)
TBR: dpapad@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/1299783
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/branch-heads/3578@{#330}
Cr-Branched-From: 4226ddf99103e493d7afb23a4c7902ee496108b6-refs/heads/master@{#599034}
[modify] https://crrev.com/c94e97dc36eecf3413b1e22d3782844750bdf04e/chrome/browser/resources/print_preview/new/model.js
[modify] https://crrev.com/c94e97dc36eecf3413b1e22d3782844750bdf04e/chrome/test/data/webui/print_preview/settings_section_test.js

The following revision refers to this bug: 
https://chromium.googlesource.com/chromium/src.git/+/c94e97dc36eecf3413b1e22d3782844750bdf04e

Commit: c94e97dc36eecf3413b1e22d3782844750bdf04e
Author: rbpotter@chromium.org
Commiter: rbpotter@chromium.org
Date: 2018-10-25 18:50:32 +0000 UTC

Print Preview: Fix duplex defaults (M71)

Check the internals of the duplex capability, instead of only checking
for its existence, to determine whether to display the duplex checkbox.
Pull default value from the printer if it is available.

Currently a speculative fix, as have not been able to identify a
printer which sets the duplex capability field but does not actually
support duplex.

Bug: 896244
Change-Id: Iebafc3878a1e7658b821465439ee172c479ce413
Reviewed-on: https://chromium-review.googlesource.com/c/1290145
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#601790}(cherry picked from commit b0f2b8367cee08dee6f6f7c62c56c7e462877ca1)
TBR: dpapad@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/c/1299783
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/branch-heads/3578@{#330}
Cr-Branched-From: 4226ddf99103e493d7afb23a4c7902ee496108b6-refs/heads/master@{#599034}

 Issue 898823  has been merged into this issue.

Update: Merged fix to 71 above, and the finch CL has landed to turn the flag off for 69/70.

 Issue 898496  has been merged into this issue.

Still occurring on Chrome/71.0.3578.20 Safari/537.36

Seems to be related to Chrome Policy "DisablePrintPreview".
https://www.chromium.org/administrators/policy-list-3#DisablePrintPreview

Setting the group policy to "Enabled" and then back to "Disabled" seems to trigger this issue.

RE: comment 28, it doesn't look like the merge above made it into 71.0.3578.20, so makes sense that the issue still reproduces there.

 Issue 900352  has been merged into this issue.