have office jet 6968.. can print evrything except envelopes. Message on printer says,

[Moonpie5]

PRINTER WILL  PRINT ANYTHING EXCEPT ENVELOPES.  MESSAGE ON PRINTER SAYS " THE PAPER SIZE DETECTED BY PRINTER DOES NOT MATCH PAPER SIZE SELECTED FOR THE PRINT JOB

[Jeet_singh]

@Moonpie5,

Thank you for posting your query on HP Support Community,

While printing different paper sizes and envelopes. I think you need to try and change some of the paper settings to get this machine working fine for you.

Let's try these steps here: 

Adjust the paper size setting

Check the paper size setting to make sure it matches the paper you want to print.

NOTE: 

Some printers have an option to ignore the error and continue printing. If you choose to ignore the error, the margins on your printout might not be proportional to the edges of the paper.

1. In the program you want to print from, click File, and then click Print.

2. Make sure your printer is in the Name or Printers drop-down list box, and then click Properties, Printer Properties or Preferences.

3. Click the Paper/Quality tab.

4. Click Advanced, if necessary, and then click Paper Size.

   

5. Select the paper size that matches the size and type of paper loaded in the printer tray, and then click OK. If there are no matching paper sizes, select the size from the list that is closest to the size of the paper loaded in the tray.

6. Click OK, and then try to print.

You may go through the steps suggested in this support document - HP Printers - 'Paper Mismatch' Error (Windows)

Alternatively, you can go through these links : 

To change the print settings in Windows:Print Driver Settings Guide (Windows)

Printing envelopes in Windows: Printing Envelopes (Windows)

Please let me know if this resolves the issue, or if you require further assistance.

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