PIXMA TR4720 trouble printing envelope

[offbohan]

I've read Canon instructional pages and set up accordingly but print still comes out portrait – I keep going back to about 3 instructional pages re. Envelopes but the result never changes.I've tried envelope DL  and tried a custom size paper.  On some attempts  I get a window that wants me to move the blue paper-size sliders on the printer so that is blocking progress.   I can't keep wasting special envelopes.  

[offbohan · Accepted solution]

I gave up !   so I downloaded Tweaking Envelope Printer  .  After familiarizing myself for 10 min. I completed my Christmas card envelopes tonight - no further problems. 

[Bricemb96]

Yeah I posted the same inquiry and that was about a year ago and @Canon support is useless and very unhelpful.