How to design a blind box series: how many figures, what secret ratio, and how to pack a case

This guide walks through the structure of a series with real examples from Pop Mart's product pages and other sellers, the arithmetic that sits behind them, and the practical points about production that matter once you move from sketches to a factory.

It covers structure and operations, not the legal side: odds disclosure, lottery law and marketplace rules belong with our guide to selling blind boxes in the US, and product-safety testing is in the same compliance guide. Treat anything here about legal exposure as a prompt to ask a lawyer, not as advice.

What a series is made of

A blind-box series has a few building blocks. There are regular designs, which make up most of the production. There may be one or more rarer versions, often called special, hidden, chase or secret figures. And there is the packing rule that decides how those figures are distributed into boxes and cartons.

Pop Mart's own product pages show how much those pieces vary. The listings below are from Pop Mart's Australian store and from US and Singapore retailers, and the ratios are the ones printed on those pages.

Two things stand out. The 12-plus-1 layout is common but not universal, and the secret ratio is a design choice that Pop Mart changes from series to series, from 1 in 72 to 1 in 288 on these pages. There is no standard you must copy. There is only the discipline of picking numbers, stating them, and making production match.

Choosing the number of regular designs

More designs make a series feel richer and make completing it harder. The arithmetic is worth seeing before you commit. If a buyer draws boxes one at a time from a series of 12 equally likely regular designs, the expected number of boxes needed to see all twelve is about 37. Twelve boxes drawn at random produce on average about 7.8 different designs, so roughly four of the twelve are duplicates. Those are averages from a simple model that ignores collation, and a particular buyer can do much better or worse.

That duplicate rate is not a flaw. Duplicates drive trading and secondary sales, and they are the reason sealed cases and full-set purchases exist. But it is the number to hold in mind when you decide between 6 designs and 12. A plush manufacturer's guide aimed at brands suggests 6 to 12 designs as enough for collecting without overwhelming buyers, which is a vendor's view, not a rule.

A smaller series completes faster and suits a lower price or a new brand that is still earning attention. A larger one gives collectors more to chase and costs more to design, sculpt and tool, since each regular design generally needs its own mould or sculpt. Our costs guide shows how that per-design tooling cost lands in a real first run.

Choosing the secret ratio

The ratio is the probability, per box, that a given box holds the secret. A ratio of 1/144 means that on average one box in 144 does. The chance that a buyer sees it at least once in n boxes is 1 minus (1 minus 1/ratio) to the power n. Here is what that looks like for the three ratios that appear on the pages above.

These are probabilities for independent random draws. They are also a reminder that even at 1/72, a buyer who opens 72 boxes has about a one-in-three chance of never finding it. Whether that is exciting or infuriating depends on price. A series priced near $10 can carry a harsher ratio than one near $27, because the cost of the hunt is lower. Our pull-rate guide works the same arithmetic from the buyer's side.

Kidrobot-style artist series that sell around $12 to $15 in the US are reported to print a ratio for every figure, and one licensed box is reported to place its rarest designs at 1 in 24. That report is from a retailer-tools blog, so check Kidrobot's own listings before you cite it.

Be careful with a number you picked to sound rare. A vendor guide for plush brands recommends 1:72 or 1:96, and a vendor's recommendation tends to follow what the vendor already knows how to pack. Choose a ratio you can print, afford, and keep true across production runs. A ratio that changes between batches, or that your factory cannot reliably hit, is a problem for you and for any marketplace that asks you to state odds.

The case: where most confusion starts

Buyers see boxes. Factories ship cartons, and the carton is where your promises become real or not. StockX describes sealed cases as factory-packed assortments from one series, usually 6, 8 or 12 boxes, often packed to reduce duplicates, with a secret that may replace a standard figure rather than being guaranteed.

Pop Mart's pages show that same logic and its variations. On the Transformers Generations page, a set of 12 boxes yields all 13 designs, meaning the 12 basic figures and the surprise. On the Loong series, a set of 12 gives 11 basic figures plus one special, or 11 basic plus one secret. On the Kubo Jeans page, a set of 12 gives 12 different designs.

So there are at least three different promises hiding behind the word set. You need to decide which one is yours, write it down in plain words, and make sure the factory's collation matches it. A plush manufacturer describes carton sizes of 48, 72 or 96 pieces, which suggests that carton size is typically set to fit the rarity maths. That is another vendor claim, but the principle holds: if the secret ratio is 1 in 144 and your carton holds 72, a decision has been made about how secrets are spread across cartons, and someone should be able to tell you what it is.

Production points that affect the structure

Factory websites quote minimums and lead times that are useful for planning, with the caveat that they are marketing figures. Weijun Toys says it typically requires 3,000 units for plastic figure blind boxes and 500 for plush, with 6 to 8 weeks after sample approval. An Alibaba sourcing guide gives 3,000 to 5,000 units as the usual minimum for existing designs and 10,000 or more for fully custom moulds, with 6 to 8 weeks for original mould development. Our costs and suppliers guides go deeper on this.

The structural point is that a series of 12 regular figures plus a secret has to fit inside whatever minimum applies. Ask whether it is per order or per design, and decide how the units split across designs before the factory begins.

Another Alibaba sourcing page says buyers can ask for serial tracking or video of the packing process to confirm that distribution is fair, and the first guide lists AQL inspection at 2.5% during packing among the checks to ask about. Both are supplier-side suggestions, and neither is a substitute for opening a sample of sealed cartons yourself and counting what is in each. If you promise a ratio, an audit of a few cartons before shipment is cheap compared with relabelling a thousand boxes.

1. Fix the design list and the ratios in writing before tooling starts.
2. Ask for the collation plan in writing, including how secrets are distributed.
3. Have the factory pack a pilot carton, open it in front of you or on video, and compare it with the plan.
4. Make the printed ratio on the box match the production plan, not the other way round.

What you tell buyers

Pop Mart prints series structure and ratios on its product pages, and so do the retailers above. That openness is partly habit and partly pressure: TikTok Shop's conditions for mystery boxes are reported to include disclosure of unequal odds, and other countries are discussing mandatory disclosure. Our compliance guide covers what the US rules actually require.

Even where no rule applies to you, publishing the figures costs nothing and prevents the argument later. Put the number of designs, the ratio of each tier and your set rule on the box and the listing, in the same words.

Avoid pitching the secret as a reason to buy. Marketing that leans on the chance of a prize is what draws scrutiny in the lottery-law discussion, and it sets expectations that a 1 in 144 ratio will disappoint most buyers. Sell the characters.

Structure will not rescue a weak character

The mechanics are copyable. The character is not. Pop Mart reported that The Monsters, the franchise that includes Labubu, brought in 14.16 billion yuan in 2025, while Twinkle Twinkle and Hirono generated 2.06 billion and 1.74 billion yuan. KrASIA, citing the company's annual meeting, reported that 49% of new members recognised only Labubu 3.0, and media reports at one point showed weak sales for a new IP's blind boxes on e-commerce platforms. The same company, with the same structure, sees very different results depending on the character.

The price side tells a similar story. China Daily reported that Pop Mart's Merodi After School series launched in late February 2026 with 12 figures and a secret at 69 yuan a box, or 828 yuan for a full set, which is simply twelve times 69. A separate report citing the Dewu resale app said the secret rose to a peak of 374 yuan. That is one data point from one app at one moment, and as the Labubu resale market has shown, premiums can fall quickly. Build a series you would be proud of if every figure were a regular.

A one-page plan

1. Pick the tier structure: number of regular designs, whether there are specials, and how many secrets.
2. Choose a ratio for each tier you can print and the factory can pack. Run the probability table for the price you intend to charge.
3. Write the set rule in one sentence, for example whether a set of 12 gives 12 different designs.
4. Get the collation plan from the factory in writing and test it on a pilot carton.
5. Print structure and ratios on the box and the listing, with identical wording.
6. Check product-safety testing and platform rules before you place the main order.

Questions founders ask

Sources and further reading

• Pop Mart, US product pages — the series structures and printed ratios in the first table, as published on the product pages we read.
• StockX, sealed-case guidance — factory-packed assortments, usual case sizes and how a secret may replace a standard figure.
• KrASIA and China Daily reporting on Pop Mart's 2025 franchise revenue, member survey and the Merodi After School launch pricing (February 2026).
• A plush-manufacturer guide and Alibaba sourcing guides for MOQ and carton-size figures; those are vendor claims and are labelled as such above.
• Our factory verification checklist covers how to check that the supplier you pick can actually hold a collation plan.