#9 Envelopes are commonly used for sending donations, payment vouchers, and invoices. The size of standard #9 envelopes is 3 7/8 x 8 7/8 inches, making them perfect to fit into #10 envelopes, for return mailings.  These envelopes are suitable for home or office mailing projects, and are available in a variety of colors, ranging from pastels to bright. Several different options are available in the #9 envelopes, including window, regular, invitation, and security tinted.

• #9 Remittance envelopes
  The #9 envelopes are suitable for charity donations or fundraising events. They are often used by non- profits, political campaigns, churches and similar organizations, and include a unique wallet type flap.  These envelopes include peel and seal, or moistened glue sealing options.The most popular standard #9 envelope is the 24lb white wove.  A stunning appeal message or image can be printed on the envelope in color, without incurring significant additional costs. When opened, the image area is 7.750 x 8.875. To gain added attention, these envelopes come in the following pastel colors; blue, gray, green, pink, goldenrod and cream.
• # 9 Regular envelopes
  #9 envelopes are the most commonly used commercial-sized envelopes, and are suitable to use for reply mailing and business-related mails. These envelopes can be sent to recipients inside of #10 envelopes, in order to mail something back to the sender.  #9 envelopes are available in a wide range of colors, including bright white, midnight black, and pastels.  With a commercial flap, these are a great option for automated inserting fulfillments such fliers, postcards, brochures and notices.
• #9 Double window envelopes
  Double window envelopes contain two transparent windows, which makes them the ideal choice for legal documents, invoices, or business mailings. These envelopes include blue security tint, and have peel and seal, or moistened glue sealing options.