#10 Square Flap Envelopes w/Peel & Press (4 1/8 x 9 1/2) - Midnight Black (250 Qty.) | Business | For Checks, Invoices, Letters & Mailings | Printable | 80lb Text Paper | F-4560-B-250 Size: #10 Square Flap Envelopes 4 ? in x 9  in / 4.125 x 9.5 / 104.775mm x 241.3mm Quantity: Pack of 250 Color: 80lb. Midnight Black is a deep black color. This envelope is made from quality 80lb. Text Paper. Opaque and not see through. Modern Square Back Flap. USES: Checks, Invoices, Letterhead, Personal Letters, Statements, Bills, Flyers. Applications: Business Mailings, Direct Mail, Corporate Mailings, Financial Mailings, Personal Mail. Printable on off-set printing presses and some home printers.