Rigid All-Board Envelopes – Box of 100. C3 Board Envelope-Very strong all-board envelopes that provide excellent protection for items such as negatives, photographs, diaries, books, calendars, photocopies and printouts etc. Printed “Please do not Bend” in three languages. Gussetted envelopes to take bulky items such as books, videos and CDs etc. Each envelope features a self adhesive closure and an easy to use perforated tear-off tab. Additional hole provided for sealing with brass tag if preferred. For our full range of packaging products, click here.