BOARD BACK BACKED ENVELOPES C3 C4 C5 C6 *ALL SIZES*
(C6 / C5 / C4 / C3) AND ALSO IN MM. NO OF ENVELOPES) - ALL AT THE BEST PRICES! Product Type: Strong Board Back Envelopes. Strength of board is 1050mu (very strong). C4 Board Back Envelopes - 324mm x 229mm.