Kraft paper outer structure, internal foam lining structure for extra protection during transit, ensure the packages arrive in great condition. Whether you are thinking of mailing documents or something else, these padded sturdy envelopes should be your first choice. These bubble lined envelopes are lightweight and do not add to your shipping costs. Padded envelopes are completely opaque and protect the shipped item from prying and curious eyes. You can mail sensitive documents without fear in these bubble mailers. These mailer envelopes can be used in offices, at home, in shops, schools and everywhere where there is a need for shipping.