Mailer Box Guides
Plain answers to the questions that come up most when sellers order their first printed box.
Mailer Box Sizes and Royal Mail BandsWhich inside sizes land in Large Letter, Small Parcel and Medium Parcel, and how to stay in the cheaper band.
E-Flute vs B-Flute: Which Board for Your Mailer BoxHow the two corrugated grades differ in thickness, print, fold and protection, and which to pick.
Printing Inside the Lid of a Mailer BoxWhat inside print can do, how it is set up on the dieline and what it adds to the job.
Mailer Box Inserts for Fragile GoodsDie-cut board inserts, dividers and void fill for glass, jars and ceramics sent by post.
How to Measure a Mailer BoxInside size, clearance and board thickness, and how to send a size we can quote.Where should you start?
If you have not ordered a mailer box before, read the measuring guide first. Most problems with a first order come from a size taken from the outside of an old box.
Then read the postal bands guide if you post slim parcels, the board guide if your box is large or your product heavy, and the inside print and inserts guides when you are planning the finish.
Who writes these guides?
The same team that quotes your boxes and draws your proofs. The guides answer the questions we are asked most, so you can arrive at the quote request form for mailer boxes with the details already worked out.
Questions
Which mailer box guide should I read first?
The measuring guide. A correct inside size makes every later choice simpler, from the band to the board.
Are the guides based on UK postal bands?
Yes. The size advice uses the Royal Mail Large Letter, Small Parcel and Medium Parcel limits. Check the current band limits before you order.
Is there a guide that explains board thickness?
Yes. The E-flute and B-flute guide compares the two thicknesses and says when the thicker board is worth it.
Do the guides cover printing inside the box?
Yes. One guide is about printing inside the lid: what fits there, how it is set up on the flat net and what to check on the proof.
Is there advice on posting glass and jars?
The inserts guide covers die-cut board inserts, dividers and paper void fill for fragile items.
Do the guides include padded mailers?
Not in depth. The padded and compostable mailer pages explain sizing and print for soft mailers.
Can I ask a question that the guides do not answer?
Yes. Email, call or send a WhatsApp message and we reply on the next working day at the latest.
Are the guides updated when band limits change?
We review them, but band limits are set by Royal Mail, so check the current figures on its site before you order.
Do I need to read every guide before ordering?
No. Send what you know and we fill the gaps when we quote. The guides simply help you make choices faster.
Do the guides recommend specific box styles?
Each guide links to the box styles that suit its topic, so you can move from advice to a product page in one step.
Your question is not here? Ask on WhatsApp or call +44 7578 382054.
Tell us what you post
Send the product, a rough inside size and a quantity. We reply in writing within one working day with a price and a free design proof. Prefer to talk? Call +44 7578 382054 or message us on WhatsApp.