Often known as catalog envelopes, these white open ends 6 X 9 envelopes are perfect for everyday office use. These envelopes are much larger than regular #9 and #10 office envelopes and they can fit an unfolded piece of document measuring 5.75 x 8.5 inches. The pure white color of the envelopes makes them ideal for sending formal letters, reports, invoices, product catalogs, and other official documents. These envelopes are made from 24 lbs white stock paper, which offers a nice blend of durability and value. The envelopes come with traditional moisture-activated gummed seals and they have a blank windowless design.