Word problems printing custom envelope sizes

[MS]

I have tried every way I know to print on an A9 (5.75 x 8.75in)
envelope on Word 2007. Every time I try, my printer displays a
message saying "incorrect paper size or type" and cancels the print.

Does anyone know of any solutions or templates to use to fix this
problem?

 

[Bob I]

If your printer physically can't handle that size, your options are,

1. Use Labels
or
2. Tape the envelope to something of a size the printer WILL handle.
or
3. Acquire a printer that WILL handle that envelope size.