postal mailer boxes

Postal mailer boxes are corrugated boxes that fold from a flat blank into a lidded parcel with a front tuck closure, protecting online orders through the post while presenting them neatly when opened. Custom Postal Boxes makes postal mailer boxes in custom sizes with custom printing, low minimum order quantities, free design support and free UK delivery.

How postal mailer boxes are constructed

A mailer starts as one flat piece of corrugated board, cut and creased so the sides fold up and the lid folds over, with side wings that tuck inside for strength. Once folded, the front and sides have double thickness in the places that take knocks, and the lid closes with a tuck tab that holds without tape on many orders.

Because the boxes arrive flat, they store in a fraction of the space of made up cartons and fold in seconds at the packing bench. A practised packer can fold, fill, close and label a mailer in well under a minute, which matters when an afternoon dispatch run contains dozens of similar orders.

Board flutes in plain terms

Corrugated board gets its strength from a wavy fluted layer between two flat sheets. A fine flute gives a smoother printing surface and a slimmer box, suited to lighter goods and sharp artwork.

Closures, seals and easy opening

A plain tuck closure is simple and reusable. A self sealing strip removes the need for tape and speeds packing. A tear strip gives the customer a clean opening line that does not tear the printed lid.

Choosing sizes for postal mailer boxes

Size the mailer from the inside out. Place the product as it will be packed, measure its length, width and height, and add clearance for any tissue, wrap or insert you always use. Then check the finished outside size against your usual postage band. Royal Mail Small Parcel allows up to 450mm by 350mm by 160mm and 2kg, and many mailer orders are designed to sit comfortably inside that band. Explore cardboard mailer boxes for the core format and letterbox postal boxes for slim orders that must pass through a door.

Avoid the two common sizing mistakes. A mailer that is too deep for its contents wastes postage and lets the product slide. A mailer that is too shallow bulges at the lid, weakens the closure and can push the parcel into a higher postage band once taped.

What postal mailer boxes suit best

Clothing, boxed cosmetics, candles in their own packaging, books, stationery, accessories, subscription orders and gift sets all suit mailers well. Very heavy items, large fragile pieces and orders with many separate components may suit a stronger shipping carton instead, sometimes with a mailer or presentation box inside for the opening experience.

Printing and packing postal mailer boxes well

Print the outside for recognition and the inside for the message. A logo and a simple design on the lid survive handling and are what the customer and their household see first. Inside the lid is the place for a thank you, care guidance or a prompt to share the purchase. The tear strip mailer boxes and self seal mailer boxes styles show how opening and sealing features combine with print.

Pack with the heaviest item at the base, keep fragile pieces away from the corners, and close the lid without forcing it. If the lid will not sit flat, the box is too small and a larger size will protect better and may post more cheaply than a bulging smaller one. Request a quote via the contact page with your product sizes, typical order weight and quantities.

FAQs about postal mailer boxes

Postal mailers are simple in use, but buyers still ask about board, sizes and sealing. These answers cover the basics.

Do postal mailer boxes need tape?

Many mailer boxes close securely with their tuck tab alone for light and medium orders. Tape or a self sealing strip adds security for heavier contents, valuable items or parcels travelling a long way. If customers may need to return items, a closure that can be opened and reused without destroying the box is the better choice.

What board are postal mailer boxes made from?

They are made from corrugated cardboard, with a fluted inner layer that cushions the contents and gives the folded box its strength. A finer flute suits lighter goods and detailed printing, while a stronger grade suits heavier or more fragile orders. Share your product weight and how you post when you request a quote so the board can be specified correctly.

Can postal mailer boxes be printed inside and outside?

Yes. Outside print makes the parcel recognisably yours on arrival, and inside print carries an opening message, care guidance or returns information where the customer will read it. Full colour and single colour options are both possible depending on your artwork. Free design support helps place the design correctly on the flat mailer template.

How do I choose between two mailer sizes?

Pack a real order in each candidate size, including the wrap and inserts you normally use. Choose the smaller size only if the lid closes flat without force and the product cannot slide. If you must press the lid down or the corners bulge, choose the larger size. A bulging parcel risks a higher postage band and a weaker closure.

Custom Postal Boxes is a project of Vertex Packaging based in Wolverhampton, manufacturing postal packaging in house for UK online sellers.