HP 1500 Series - Manual (Page 119)

ENWW Appendix C Print media specifications 117
Envelopes with double side-seams
Double side-seam construction has vertical seams at both ends of the envelope rather than
diagonal seams. This style might be more likely to wrinkle. Be sure the seam extends all the way
to the corner of the envelope as illustrated below.
Envelopes with adhesive strips or flaps
Envelopes with a peel-off adhesive strip or with more than one flap that folds over to seal must
use adhesives compatible with the heat and pressure in the printer. The extra flaps and strips
might cause wrinkling, creasing, or even jams and might even damage the fuser.
Acceptable
Unacceptable