Packaging Dimensions: 2 cm of Thickness Costs You 35 Cents

Packaging dimensions are a margin decision, not a matter of taste

Packaging dimensions decide what you hand over on every order, and the difference is not in the rounding. The FBA rate card that applies from 1 July 2026 charges EUR 3.26 in the Dutch store for a unit up to 960 grams in a large envelope, and EUR 3.61 for exactly the same unit in an extra-large envelope. That is EUR 0.35 of difference. Same weight, same footprint, two centimetres more thickness.

That is the whole decision. No material choice, no print technique, no sustainability story. Two centimetres.

For a brand doing a thousand orders a month that adds up to three hundred and fifty euros a month and well over four thousand euros a year. That is a product shoot. That is half the budget for a brand book. And it leaks away on air inside a box nobody has measured.

We see this pattern at almost every brand that expands from its own webshop onto bol and Amazon. The packaging was designed for the owned channels, where the format is free and the carrier only looks at the parcel. Then that same packaging goes onto the marketplace unchanged. Except the marketplace settles up differently: not per shipment, but per unit, per tier, per centimetre. In six years of Oase Creative we have guided more than 200 brands on bol, Amazon and Shopify, and the conversation about packaging design almost never starts with the dimension. It starts with a moodboard.

That is the wrong order. A packaging brief that starts with a moodboard locks the design in before the cost structure is known. A brief that starts with a dimension sheet leaves open all the creative room that still exists inside the tier. That is a different way of working, not a smaller one.

The envelope tiers share one footprint, only the thickness differs

The most striking thing about the EU rate table is what does not change. Every envelope tier has exactly the same maximum footprint: 33 by 23 centimetres. The light envelope, the standard envelope, the large envelope and the extra-large envelope differ on precisely one axis. The rate card puts those thickness ceilings at 2.5, four and six centimetres respectively.

That means your length and width buy you nothing as long as you stay inside the footprint. Your entire optimisation sits in the third dimension. A brand that makes its box flatter drops a tier. A brand that adds a millimetre of filler board climbs one.

What this table shows is a ladder with uneven steps. Between light and standard there is only weight. Between standard and large there is one and a half centimetres of thickness. Between large and extra-large there is two centimetres. And the jump to small parcel suddenly gives you room in the width, but costs you more than all the preceding steps at a lower permitted weight.

The practical lesson is counterintuitive: your product does not have to get smaller. Your packaging has to get flatter. Those are two different design assignments. With the first you start working on the product and you touch the proposition. With the second you start working on the construction and the product stays intact. We always take the second route first, because it is cheaper and quicker to test.

What do two extra centimetres of box thickness cost on Amazon?

At equal weight and equal footprint, the jump from the large to the extra-large envelope costs EUR 0.35 per unit in the Dutch store. Moving on to the small parcel costs another EUR 0.42 per unit on top of that, while the permitted weight in that tier is actually lower.

Set that against your order volume and it becomes a line on your profit and loss account, not a detail:

This is money that never shows up anywhere as a problem. There is no notification, no warning, no red panel in Seller Central. The fee is simply deducted, every order, for years. Brands only find out when somebody puts the rate card next to their own dieline.

And there is something else on top. Since 17 April 2026 a fuel and logistics surcharge of 1.5% applies to the fulfilment fees in the Dutch store among others. That percentage is calculated on your fee, so on the tier you sit in. Anyone sitting one tier lower also pays the surcharge over a lower amount. The effect is small per order and structural over a year.

The sum you get out of this is usable in a quotation. A construction redesign that drops you a tier pays for itself within a few months at a thousand orders a month. That is one of the few design decisions whose return you can calculate in advance instead of estimating afterwards. There is more on that in what packaging design returns in e-commerce.

PostNL allows more than Amazon, on all three axes

This is where Dutch brands consistently go wrong. The best known packaging rule in the Netherlands is the letterbox dimension, and that dimension comes from the carrier. PostNL allows a letterbox parcel up to 38 × 26.5 × 3.2 cm, at a weight of up to 2 kilos. That is the dimension most mailers in this country are drawn to.

Put it next to Amazon's narrowest envelope tier and the gap is there on every axis:

Five centimetres longer, three and a half centimetres wider, seven millimetres thicker. A mailer designed exactly to the PostNL dimension sails through the letterbox and lands at Amazon in the large envelope instead of the standard envelope. You then have a pack that works perfectly on your own channel and is structurally too expensive on the marketplace.

The comparison continues further up the ladder. An ordinary PostNL parcel may be up to 100 × 50 × 50 cm, a dimension Amazon's small parcel does not come close to. So the carrier is more generous than the marketplace at every level. Anyone taking the carrier as their design frame is by definition designing too generously for the channel where the fee is settled per centimetre.

That is not a criticism of PostNL. It is a difference in business model: a carrier charges per shipment and benefits from volume, a marketplace charges per unit and benefits from density in the warehouse. The binding dimension is therefore always the one from the strictest channel you sell on.

The dual channel mailer: one dimension for your webshop and the marketplace

The answer is not two packs. Two packs mean two dielines, two print runs, two minimum orders, two stock positions and two versions of your brand image that have drifted apart within a year. For most brands we work with, that costs more than the rate difference they are trying to avoid.

The answer is one dimension, set on the strictest channel. Concretely: draw the mailer to the smallest envelope tier your product fits in and use that same mailer on your own webshop. It then fits through the letterbox, because the PostNL limit is more generous, and it lands at Amazon in the cheapest tier that is achievable. One dieline, one print run, one brand image, two channels.

That does require you to fix the dimension before the design starts, not after. In practice it means the first deliverable of a packaging project is a dimension sheet: closed external size, external size including closure, internal size, material thickness, and the tier that produces on every channel the brand sells through. Only then do we start drawing.

What you gain from that is not just money. You also gain consistency. A customer who orders from your webshop and later through the marketplace gets exactly the same pack in the post. That is precisely the kind of coherence we set out earlier in product content across channels: one brand promising the same thing everywhere, instead of three separate executions that happen to share a sender.

And it sharpens the conversation with your printer. A printer who knows the closed thickness has to stay under a hard limit picks a different board, a different closure and a different folding sequence than a printer who is handed only a format and a print run.

Amazon measures the closed box itself, so your insert foam counts

What many brands underestimate is who sets the dimension. It is not you. The rate card states that Amazon may carry out its own measurement and that this measurement prevails. Measuring is done on the ship ready pack: closed, filled, with everything in it and on it.

That is an important detail, because it means the tier is not determined by your dieline but by your final pack. Everything sitting between the product and the outer wall counts:

• Insert foam and die cut filler board, often two to four millimetres per side
• A sleeve around the box, usually half a millimetre to a full millimetre
• Tissue paper, which bulges the moment the product is laid in it
• The closure itself, because a double flap with a sticker builds up
• An enclosed card or flyer, which stops the box closing quite flat

Four of those five are brand decisions. Precisely the things that make the unboxing moment are also the things that drive up the thickness. That is why this conversation has to happen early and not at the end, once the brand image has been signed off and the dieline is already with the printer.

The answer is almost never "take it out". The answer is usually "solve it flat". Printing on the inside of the flap instead of tissue paper. A die cut holder made from a single layer of board instead of foam. A QR code on the inside instead of a loose card. The unboxing moment stays, the millimetres come off. That is construction work, and it is the reason we never treat a dieline as a technical annexe but as part of the design itself, just as with designing recyclable packaging, where the material structure steers the design just as much.

Does the SIPP discount apply to Dutch sellers too?

No, and this is one of the few things the rate card is completely clear about. Beneath both the table with the discount for units shipped in their own packaging and the table with the packaging surcharge for oversize products sits the same footnote: the scheme does not apply to the Netherlands, Poland, Sweden, Belgium and Ireland. The discount runs in the stores of the United Kingdom, France, Germany, Italy and Spain.

That cuts both ways. A Dutch seller misses out on the discount, which runs up to EUR 0.31 per unit in the German store and EUR 0.35 in the Spanish one on the heaviest standard parcel. But that same seller also avoids the surcharge charged in those stores for oversize products without ship ready own packaging, running from EUR 0.67 for small oversize to EUR 2.58 for the heaviest standard class.

For the design, that means something very concrete. If a brand sells exclusively on amazon.nl, a SIPP certification returns nothing. Zero. Anyone selling that as a sustainability gain is selling air. The programme itself is not a new idea, incidentally: Amazon confirms it is the renaming of what was previously called Frustration-Free Packaging and Ship in Own Container, with a minimum dimension of 6 by 4 by 0.375 inches and lab testing for fragile items, sharp objects and liquids.

Where it does become relevant is on export. The moment a client switches on Pan-EU, or supplies from the German, French, Italian, Spanish or British store, the sum changes. Ship ready design is then no longer a soft sustainability claim but a rate line. So we handle it as an export question in the intake, not as a standard component. The question runs literally: are you selling outside the Netherlands through FBA, now or within twelve months? If the answer is no we skip it and say why. That saves the client money and it saves us a story that does not hold up.

With a letterbox parcel, the outside is the brand experience

The moment you design to the envelope tier, something disappears that many brands had invested their brand experience in: the outer box. On a classic shipment there is a neutral brown box around it and the brand experience sits on the inside. With a letterbox parcel there is no outer box. What the customer pulls out of the letterbox is your pack. There is no second layer to make up for it.

That changes where the design budget should go. The outside of the mailer is then shipping pack, shelf moment and unboxing moment all at once. It also spends a day with the delivery driver, comes into contact with damp and dirt, and gets pushed through the letterbox flap. A design that only looks good on a render will not survive that.

In practice that means three things. Pick print that tolerates scratches instead of a finish that holds every fingerprint. Put the brand name on the face that becomes visible first as it is pulled from the letterbox, not on the face that looks best in a presentation. And account for the tear strip, because it often cuts straight through your image area.

There is a second opportunity here that most brands leave on the table. If the mailer is the brand object itself, it is also photographable. A branded mailer in the listing gallery shows scale, quality and care in a single image, without making a claim. That works harder on the marketplace than an extra block of copy, and it is exactly where product photography and product listing design meet. The brand project for NoWhey showed the same principle: the pack was the image, not a backdrop for the image.

There is a limit to it as well. A window, an emboss or a thick laminate layer do what they promise visually, but they build up in the third dimension. That turns the unboxing moment into a trade off rather than a wish list. What it delivers in attention is known from research, as we described in where the buyer looks on a pack. What it costs is in the rate card. Both belong on the table when the choice is made.

How a packaging brief starts with a dimension sheet

A brief that starts with the dimension looks different from most briefs. It does not open with "premium, minimalist, natural", but with five lines everyone around the table understands.

One: fix the channels. Which channels now, which within a year. Own webshop, bol, amazon.nl, foreign stores. That determines which dimension is the strictest and therefore binding.

Two: measure the product, not the box. The real external dimensions of the product, including cap, protruding parts and the orientation in which it lies flat. Many products are flatter than their current packaging suggests, because that packaging was once built around the wrong axis.

Three: set the target dimension and the target tier. Pick the fee you want to land on and work back to a maximum closed external dimension, with margin for the closure. This is the number the entire design hangs on.

Four: budget the build up. Material thickness, insert, sleeve, closure, leaflet. Add up what each element contributes to the third dimension. Whatever does not fit has to be solved flat or taken out.

Five: only then the moodboard. Colour, typography, material and finish get all the room they need, inside a shell whose cost is already fixed.

This order costs more time in the first week and far less in the months after. A brand that discovers halfway through that its box is one tier too thick throws away a dieline, loses a print round and pushes back a launch. A brand that starts with the dimension loses nothing in creativity, because the constraint sits on one axis and not on the design. Our brand work for Castagnola proved it again: the sharper the technical frame up front, the freer the visual choices afterwards.

What you also buy with this is a defensible conversation with your printer and your fulfilment partner. Everyone works from the same number instead of from the same feeling.

Fix the dimension first, then the design

Brand design and the rate ladder are not opposites. They are two columns in the same document. The brand determines what the packaging looks like, the tier determines the volume that may happen inside. Put those two on the table at once and you get a pack that looks good and does not quietly leak margin on every order.

At Oase Creative every packaging project therefore starts with the dimensions and only then with the image. We work out the tier for every channel the brand sells on, fix one dimension for webshop and marketplace, and design inside it. That produces a stronger design more often than you would think, because a hard constraint forces sharper choices than a blank sheet.

Is your packaging running through the more expensive tier right now? Measure the closed box at its thickest point, hold that number against the table above and you will know within a minute. If you want us to look at your packaging design and work the dieline through at tier level, book a call. We start with the dimension.