Board Backed Envelope. AIR CUSHION & LOOSE FILL ECO (29). HB229M - C5 Manilla Board Backed Envelope 229mmx x 162mm 115gsm. HB324M - C4 Manilla Board Backed Envelope 324mmx x 229mm 115gsm. HB457M - C3 Manilla Board Backed Envelope 457mmx x 324mm 115gsm.
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