Usable size of black bubble mailers: 4x7 inch, 50 pcs. It is ideal for packaging small business. Famagic bubble mailers are a reliable shipping solution, and provide more options to meet the diverse needs of customers. Our 4x8 inch bubble mailers are widely used in online business, since outstanding color and smooth touch of the padded envelopes could give a deep impression to customers. Bubble mailers could be applied to commercial and non-commercial use.