#10 Square Flap Envelopes w/Peel & Press (4 1/8 x 9 1/2) - 70lb. Bright White (50 Qty.) | Business | For Checks, Invoices, Letters & Mailings | Printable | 70lb Text Paper | 4860-70W-50 Size: #10 Square Flap Envelopes 4 ? in x 9  in / 4.125 x 9.5 / 104.775mm x 241.3mm Quantity: Pack of 50 Color: 70lb. Bright White is our thickest and brightest white envelope color. Perfect for a professional, high quality look. This envelope is made from quality 70lb. 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.