#9 Blue Regular Envelopes - Colored Envelopes Return Letter Size Documents - Blank 3 7/8 x 8 7/8 Colored Business Envelopes (Pack of 100) TRADITIONAL GUMMED FLAP: Simple and effective sealing. The V-shaped flaps of these blue colored no 9 envelopes are lined with moisture sensitive gum. The moistenable glue flap delivers a secure hold and can hold up to the rigors of rough postal handling. HIGH PAPER QUALITY: These number 9 envelopes are manufactured from high quality paper that offers a great blend of affordability and durability. PERFECT REPLY ENVELOPES: These small return envelopes fit perfectly inside larger #10 envelopes. This makes them ideal reply envelopes. CLASSIC FORMAL STYLE: The dual diagonal seams and conventional V-shaped flaps give these colored number 9 envelopes a classic appearance. They can be used for sending both business documents and personal letters. ECONOMY PACK: This pack of 100 Blue colored business envelopes offers a great value for money. This pack is perfect for both business and personal use.