#11 Regular (blank)
Number 11 regular envelopes are slightly larger than the standard business #10 envelope. If you want to use the #10 as return/reply you will want this envelope. A #10 will fit inside a #11. It has more room then the #10 allowing for additional folded pages. It is small enough to qualify as a letter so it will not cost extra for postage based on size. Other common uses for the #11 include using them for patient records and media kits. These #11 regular envelopes are inkjet and laser printer friendly.