LUX 5 1/2 x 7 1/2 Booklet Envelopes in 24lb. Bright White are perfect for mailing Checks/Invoices/Letterhead/Personal Letters/Statements/Direct Mail, sold as 250 per box..Comes in 24lb. Bright White.USES: Checks, Invoices, Letterhead, Personal Letters, Statements, Bills, Flyers. Applications: Business Mailings, Direct Mail, Corporate Mailings, Financial Mailings, Personal Mail..Sold as 250 per box.Dimensions: 5.5"L x 7.5"W.LUX 5 1/2 x 7 1/2 Booklet Envelopes in 24lb. Bright White are perfect for mailing Checks, Invoices, Letterhead, Personal Letters, Statements, Direct Mail and more!.When you can’t or shouldn’t fold the contents, here’s the professional way to send flat but bulky materials- pamphlets, brochures, sales literature, booklets, annual reports, magazines, or catalogs. The flap, usually rectangular in shape, is on the long side for easier filling. 16 sizes in Kraft, white and an array of colors to suit your style. Available with moistenable flap, some with self-stick Peel & Seal;. Also see our Open End selection.