Our polypropylene envelopes are sealed on both long sides and the bottom short side. The envelopes contain enough space to hold matted prints. 4" x 5" Polypropylene Photo Envelope (in packs of 50 envelopes) $7.80, 5/$36.25, 10/$67.50 4" x 6" Polypropylene Photo Envelope (in packs of 50 envelopes) $8.35, 39/$10.00, 72.5/$0.00 5" x 7" Polypropylene Photo Envelope (in packs of 50 envelopes) $10.90, 5/$5.00, 52/$10.00, 99/$0.00 8" x 10" Polypropylene Photo Envelope (in packs of 50 envelopes) $16.65, 5/$80.50, 10/$156.00 8.5" x 11" Polypropylene Photo & Print Envelope (in packs of 50 envelopes) $17.15, 5/$83.25, 10/$161.00 9" x 12" Polypropylene Photo & Print Envelope (in packs of 50 envelopes) $17.65, 5/$85.75, 10/$166.50 10" x 15" Polypropylene Photo & Print Envelope (in packs of 50 envelopes) $18.70, 5/$91.00, 10/$177.00 11" x 14" Polypropylene Photo & Print Envelope (in packs of 50 envelopes) $18.70, 5/$91.00, 10/$177.00 11" x 17" Polypropylene Photo & Print Envelopes (in packs of 50 envelopes) $19.75, 5/$96.25, 10/$187.00 12" x 18" Polypropylene Photo & Print Envelope (in packs of 50 envelopes) $20.80, 5/$101.50, 10/$197.50 13" x 19" Polypropylene Photo & Print Envelopes (in packs of 50 envelopes) $21.85, 5/$106.50, 10/$208.00 16" x 20" Polypropylene Photo & Print Envelope (in packs of 50 envelopes) $23.95, 5/$117.00, 10/$229.00