It is one of the first real decisions you make once you start sending orders out with your name on them. Does the product go in a bag, or does it go in a box? Both are printable, both are recyclable, and both will do the job for plenty of products. But they fail in different ways, and they cost different amounts to post. Getting the choice right saves you money on every single parcel, not just the first one.
Here is how we would work through it.
Start with the product, not the packaging
The useful question is not "which looks better". It is "what happens to this item if the parcel gets dropped, stacked under something heavy, or posted through a letterbox at speed".
If your product is soft, flexible, or already protected by its own retail packaging, a paper mailing bag is usually enough. Clothing, textiles, knitwear, fabric, soft toys, pouches, anything that can bend without complaining. If your product has hard edges, corners, a rigid shell, or anything that can snap, dent or crack, it needs a box around it. Ceramics, glassware, candles in jars, electronics, anything with a lid that can be pushed in.
Paper mailing bags protect against scuffing, moisture and prying. They do not protect against crushing. That is the whole distinction in one sentence, and most of the decision follows from it.
What paper mailing bags do well
Our heavy duty paper mailing bags are 2-ply 70gsm kraft with a peel and seal closure. Two layers of paper, no plastic film, recyclable, and FSC approved where applicable.
The practical advantages are speed and space. A bag is fold, peel, seal, done. A box has to be assembled, filled, void-filled and taped. If you are packing forty orders on a Monday morning, that difference is a real chunk of your week. Bags also arrive flat and stay flat, so a few hundred of them live in a corner rather than eating a shelf.
There is one thing to know before you commit. Our stock paper mailing bags carry small supplier branding at the bottom of the bag. It is not intrusive, but it is there, and it is worth knowing about when you plan where your own artwork sits.
What cardboard boxes do well
Our postal boxes use E-flute, which is 1.6mm corrugated board. That fluted middle layer, sandwiched between two liners, is the entire reason a box resists crushing when flat paper cannot. It is also why a box weighs more and costs more to post.
What you buy with that extra weight is structure. A box holds a fixed shape, so the product inside is not being squeezed by whatever is on top of it in the van. It gives you somewhere to put void fill. And it gives you a second printable surface, because we print postal boxes internally as well as externally, so the inside of the lid can carry a message the customer only sees at the moment they open it.
Boxes also arrive looking deliberate. A rigid, square parcel reads as a considered product in a way a soft bag does not, which matters more for gifting, homeware and anything at a higher price point.
Postage usually settles the argument
This is the part that costs real money, and it is where the two diverge most.
A bag takes the shape of what is inside it. Pack a flat, soft item and the bag stays thin, which keeps it in a cheaper size bracket. A box has fixed dimensions whether you fill it or not, so if you use a box that is bigger than the product, you are paying postage on empty air on every order for as long as you keep doing it.
Before you settle on either, work out which Royal Mail PiP category your parcel falls into, because the jump between brackets is usually larger than the difference in packaging cost. We categorise our boxes and mailers by PiP size for exactly this reason. If a box is the right call, our guide to choosing the right box size goes through how to measure properly and where people typically go wrong.
One caveat on measurements. Pre-manufactured stock packaging carries a manufacturer tolerance of roughly 10 to 20mm either way. If your product sits right on the edge of a postage bracket, order a blank sample and measure the actual item rather than trusting the listed dimensions.
What the printing looks like on each
Worth being straight about this, because it affects the design work you do before you order.
We print full colour onto pre-manufactured stock packaging, which is what lets us turn orders around quickly. The trade-off is that print happens in pre-defined print areas, not across the whole product. On paper mailing bags that means both sides of the bag, in the defined areas. On postal boxes it means internally and externally, again in the defined areas. You can see exactly what is available on any product by hovering the red question mark icon in the artwork upload tool on that product page. We have written up the detail in our piece on which areas of a box you can actually print on.
Two more things that apply to both. There is no white ink, so anything white in your artwork simply shows as the bare material. On brown kraft, white becomes brown. And we would steer you away from large areas of solid block colour, because printing onto an uneven kraft surface makes flood fills look patchy, more so on brown than on white. Line work, outlined type and a contained mark on bare kraft hold up far better, and tend to look more expensive anyway.
The options in between
It is not strictly a two-way choice. If you post books, prints, magazines or anything flat and rigid, book and magazine wrap mailers wrap around the product and fold to its depth, which gives you box-style edge protection without box-style bulk. Padded mailers cover the gap for small items that need cushioning but not structure.
How to decide without guessing
Order a blank sample. They cost a couple of pence, and putting your actual product into the actual bag or box answers the question faster than any amount of measuring. If you are torn between the two, get one of each.
When you do order, nothing gets printed in full until you have approved a printed sample, by email, by video or physically in the post, with unlimited amendments until you are happy. If you are not satisfied with the sample, you get a full refund. Production speed is chosen at checkout: same day locally where stock allows, next day, or the standard three to five day service. For the quicker options you need to be available to approve your proof.
