Book wraps are E-flute with a peel-and-seal strip. M-envelopes are the Tenvolope flat pack. Both are flat. They are not the same box. This page stays with postal tubes.
Packaging Boxes keeps Postal tubes apart from a square box. Tubes are their own range, for posters, plans and other rolls.
What this collects
A postal tube takes a roll without crushing it into a square.
The notes below stay on postal tubes. A square box needs fill in the corners and still presses a roll.
Before the order goes in
The tube length has to clear the roll.
TradePro at Packaging Boxes, for trade businesses, starts at 5% off and goes up to 10% when you spend over £1,000 a month, and it adds BACS. It does not change which Postal tubes you needed.