How do I stop printer from choosing the WRONG PAPER TRAYZ?

[BeniciaTim]

My MFP M281fdw (Multifunction color laserjet) keeps looking for letter-size paper in Tray 1, which is the single-fed mainly used for envelopes.  Adobe Acrobat interprets that as require envelope-SIZED paper.

[Repairatrooper]

There are several possible issues here. First, make sure that the hardware settings on the printer are correct, if you have plain letter, you must set the paper type and size to plain letter. Secondly, on the print driver, make sure that the default paper size set for tray 2 is plain letter. I have seen cases where the driver defaults to HP eco paper or A4 sized paper, which results in that tray not being selected and Tray 1 asking for plain letter. Thirdly, when printing from Adobe, ensure that you do not have the "select paper source by PDF page size" checkmarked (see picture below). This can cause issues when trying to print a document that was created with a computer that uses standard paper sizes tha differ from yours. For example A4 if a document was created in Europe.

[BeniciaTim]

Thank you for that very thorough and thoughtful reply.  I have seen the "A4" problem arise on other HP printers at my office, which I have not visited since March.

The one thing I am not clear on is how to check or change setting in the print driver.  It does seem likely to me that that is the origin of the problem -- not sending a letter-sized job for printing from Tray #2.   HPs various screens for updating drivers, some of which divert attention toward "HP Print Doctor" -- which at the moment this HP Computer and printer do not seem able to run, although my other (personal) computer has done so.  The personal PC uses WiFi because I had to remove the ethernet cable and put it in Wi-Fi mode because it wouldn't print wirelessly when the computer was attached by ethernet.  The setup files are confusing on that point, but I don't much care:  I think either way I get the printer looking for an envelope.

If I can figure out driver settings, I should be home free.   Anyway, thank you kindly for your response.

[Repairatrooper]

To manually check the settings instead of using the Doctor do this: On your PC go to control panel>devices and printers and then right click on the icon for your printer and select "printer properties" from the drop down menu. Click on the preferences button in the bottom left of the window which will open up user defaults, click on printing shortcuts and set the paper size there.

You can also click on the Device settings tab and set the paper sizes there as well.