In the previous test, I measured all 30 packs from a Japanese Munikis Zero booster box and compared pack weight with SR, AR, RR, and R results.
This time, I tested Storm Emeralda.
For this experiment, I used all 30 five-card packs from an unopened Japanese Storm Emeralda booster box that I purchased myself.
Every sealed pack was weighed individually to the nearest 0.01g. I then opened all 30 packs and recorded the relationship between pack weight and SAR, SR, AR, RR, and R results.
The results were particularly interesting.
The SAR appeared in a pack weighing 8.61g.
The SR appeared at 8.63g.
However, the heaviest pack in the entire booster box weighed 8.67g and contained an R.
Even more importantly, six different packs weighed exactly 8.61g, yet their opening results included SAR, AR, RR, R, and even a pack in which no R or higher rarity was observed.
Therefore:
Although relatively heavy packs showed some tendency to contain rare cards within this booster box, pack weight alone could not accurately identify the rarity inside an unopened pack.
This article documents an experiment into whether what is commonly known as “pack weighing” can actually distinguish card rarity.
It is not intended to encourage weighing packs in stores, selecting packs by weight before purchase, or selling packs that have been sorted by weight.
Pack weight may be affected by the foil wrapper, card surface treatments, printing, cutting variation, manufacturing differences, humidity, the measuring environment, and scale accuracy.
The measurements shown here apply only to this specific booster box.
They should not be treated as universal standards for other booster boxes, production batches, or loose packs.
About Japanese Storm Emeralda
Storm Emeralda is a Japanese expansion with five cards in each standard booster pack.
The booster box tested here produced SAR, SR, AR, RR, and R cards.
No MUR card was observed in this particular booster box.
For that reason, this article focuses only on the rarities that were actually observed after opening all 30 packs.
Test Conditions
The test was conducted under the following conditions.
- Product: Japanese Storm Emeralda expansion
- Purchase format: unopened booster box
- Number of packs measured: 30
- Cards per pack: 5
- Every pack was weighed while sealed
- Measurement precision: 0.01g
- Location: normal indoor environment
- All 30 packs were opened after weighing
- SAR, SR, AR, RR, and R results were recorded
The measured weight of a sealed booster pack includes both the cards and the outer foil wrapper.
Even cards of the same rarity may differ slightly because of printing coverage, surface treatments, cutting, and other manufacturing variation.
For this reason, the measurements below should be viewed as relative data comparing the 30 packs within this specific booster box, not as absolute rarity thresholds.
Storm Emeralda Pack Weight Results: 30 Packs Measured
The 30 packs measured in this booster box ranged from:
Measured range: 8.54g–8.67g
Average pack weight: approximately 8.59g
Difference between lightest and heaviest pack: 0.13g
Of the 30 packs, 15 contained an SAR, SR, AR, RR, or R.
The remaining 15 packs did not contain any of those rarity levels.
The 15 packs containing an R or higher rarity had an average weight of approximately 8.62g.
The 15 packs in which no R or higher rarity was observed averaged approximately 8.57g.
This booster box therefore showed a tendency for packs containing rare cards to be heavier on average.
However, looking at each rarity individually produced a much more complicated picture.
For example, the average weight of the R packs was higher than the average weight of the SAR and AR packs.
This shows that a pack containing a rare card may be heavier on average, but higher rarity does not necessarily mean higher pack weight.
What the Measurements Showed
The main findings from these 30 packs were:
- The SAR appeared at 8.61g
- The SR appeared at 8.63g
- AR cards appeared at 8.58g and 8.61g
- RR cards appeared between 8.61g and 8.63g
- The heaviest 8.67g pack contained an R
- All seven packs weighing 8.62g or more contained an R or higher rarity
- None of the eight packs weighing 8.57g or less contained an R or higher rarity
- At 8.61g, SAR, AR, RR, R, and no-R-or-higher results all appeared
- Pack weight did not increase in direct proportion to rarity
This booster box showed some tendency for relatively heavy packs to contain rare cards.
However, the highest rarity did not appear in the heaviest pack, and multiple different opening results were observed at identical displayed weights.
SAR Pack Weight
The SAR observed in this booster box came from a pack weighing 8.61g.
This was above the overall average of approximately 8.59g, but it was not one of the very heaviest packs in the box.
There were six packs weighing exactly 8.61g.
Their results were:
- 8.61g: SAR
- 8.61g: AR
- 8.61g: RR
- 8.61g: R — 2 packs
- 8.61g: No R or higher observed
The same displayed weight therefore produced SAR, AR, RR, R, and a standard result.
Even when measuring to the nearest 0.01g, there was no way to distinguish the SAR pack from the other 8.61g packs before opening.
Several packs were also heavier than the SAR pack.
Those heavier packs produced SR, RR, and R results.
The only conclusion supported by this test is:
In this booster box, the SAR was found in an 8.61g pack.
This does not mean that an 8.61g pack contains an SAR or that choosing a heavier pack will reliably identify an SAR.
SR Pack Weight
The SR observed in this booster box came from a pack weighing 8.63g.
This was toward the heavier end of the overall distribution.
However, another 8.63g pack contained an RR.
- 8.63g: SR
- 8.63g: RR
Therefore, even though the SR appeared in a relatively heavy pack, exactly the same displayed weight also produced a different rarity.
The two packs heavier than the SR measurement weighed 8.64g and 8.67g.
Both contained R cards.
This provides another clear example of why the heaviest pack does not necessarily contain the highest-rarity card.
AR Pack Weight
The AR cards observed in this booster box appeared at:
- 8.58g: 2 packs
- 8.61g: 1 pack
Their average pack weight was approximately 8.59g.
The AR cards were not concentrated exclusively toward the heaviest end of the booster box.
Five packs weighed exactly 8.58g.
Their results were:
- 8.58g: AR — 2 packs
- 8.58g: No R or higher observed — 3 packs
The same 8.58g measurement therefore produced both AR and standard results.
Another AR appeared at 8.61g, but that same weight also produced SAR, RR, R, and a no-R-or-higher result.
Therefore, no weight range unique to AR packs was identified.
RR Pack Weight
The RR cards observed in this booster box appeared at:
- 8.61g: 1 pack
- 8.62g: 2 packs
- 8.63g: 1 pack
Their average pack weight was approximately 8.62g.
RR cards were relatively concentrated toward the heavier end of the distribution.
However, each of those measurements also overlapped with other results.
- 8.61g: SAR, AR, RR, R, and no R or higher
- 8.62g: RR and R
- 8.63g: SR and RR
Although the RR results showed some concentration within a narrow weight range, those measurements were not unique to RR cards.
Therefore, RR packs could not be accurately identified using weight alone.
R Pack Weight
The R cards observed in this booster box appeared at:
- 8.59g: 1 pack
- 8.61g: 2 packs
- 8.62g: 1 pack
- 8.64g: 1 pack
- 8.67g: 1 pack
Their average pack weight was approximately 8.62g.
One of the most interesting results in this test was how widely the R cards were distributed toward the heavier end.
The heaviest pack in the entire booster box weighed 8.67g and contained an R.
The second-heaviest individual measurement, 8.64g, also contained an R.
The average weight of the R packs was higher than the averages of the SAR and AR packs.
This is another clear indication that higher rarity does not directly correspond to higher pack weight.
Packs With No R or Higher Rarity Observed
Fifteen of the 30 packs did not contain an SAR, SR, AR, RR, or R.
Their measured weights were:
- 8.54g: 2 packs
- 8.55g: 3 packs
- 8.56g: 1 pack
- 8.57g: 2 packs
- 8.58g: 3 packs
- 8.59g: 1 pack
- 8.60g: 2 packs
- 8.61g: 1 pack
Their average weight was approximately 8.57g.
In this particular booster box, none of the eight packs weighing 8.57g or less contained an R or higher rarity.
Starting at 8.58g, however, the results began to overlap.
AR cards appeared at 8.58g.
An R appeared at 8.59g.
SAR, AR, RR, and R cards all appeared at 8.61g.
At the same time, packs with no R or higher rarity were also present between 8.58g and 8.61g.
Therefore, these measurements cannot be applied to another booster box as a fixed boundary for rare-card identification.
The Heaviest Pack Did Not Contain the Highest Rarity
The seven heaviest packs in this booster box produced the following results:
- 8.67g: R
- 8.64g: R
- 8.63g: SR
- 8.63g: RR
- 8.62g: RR
- 8.62g: RR
- 8.62g: R
All seven packs weighing 8.62g or more contained an R or higher rarity.
However, neither the SAR nor the AR cards appeared among these seven packs.
The SAR appeared at 8.61g.
AR cards appeared at 8.58g and 8.61g.
This booster box therefore showed some relationship between heavier pack weight and the presence of a rare card.
But sorting the packs from heaviest to lightest did not produce the rarities in descending order.
Five Different Results Appeared at 8.61g
The most significant overlap in this test occurred at 8.61g.
Six packs showed this exact measurement.
Their results were:
- SAR: 1 pack
- AR: 1 pack
- RR: 1 pack
- R: 2 packs
- No R or higher observed: 1 pack
Every observed result except SR appeared at exactly 8.61g.
One 8.61g pack contained the SAR.
Another 8.61g pack did not contain even an R.
This is one of the clearest examples in the series showing that measurements to the nearest 0.01g cannot reliably identify what is inside an unopened pack.
Results by Weight Range
The opening results can also be grouped into several approximate ranges.
✅8.62g–8.67g: SR, RR, and R observed
All seven packs in this range contained an R or higher rarity.
However, the two heaviest packs contained only R cards, and neither SAR nor AR appeared within this range.
This result applies only to this specific booster box and should not be treated as a guaranteed rarity range.
✅8.61g: SAR, AR, RR, R, and no-R-or-higher results overlapped
This was the measurement with the greatest variety of opening results.
Both high-rarity and standard results appeared at exactly the same displayed weight.
✅8.58g–8.60g: AR, R, and no-R-or-higher results overlapped
AR cards appeared at 8.58g, but other packs at the same measurement contained no R or higher rarity.
There was no clear boundary.
✅8.54g–8.57g: No R or higher observed in this booster box
None of the eight packs in this range contained an R or higher rarity.
However, this applies only to this single booster box.
Another box may produce a different distribution.
No packs in this booster box measured 8.65g or 8.66g.
Because there is no data for those measurements in this test, no conclusion can currently be drawn about them.
Can Japanese Storm Emeralda Packs Be Weighed to Identify Rarity?
This booster box showed some tendency for relatively heavy packs to contain an R or higher rarity.
However, the complete dataset also showed:
- The heaviest 8.67g pack contained an R
- The SAR appeared at only 8.61g
- AR cards appeared as low as 8.58g
- SAR, AR, RR, R, and no-R-or-higher results all appeared at 8.61g
- An SR and RR both appeared at 8.63g
- The average weight of R packs was higher than the average weight of SAR and AR packs
- Factors other than card rarity may affect total pack weight
Based on these results, pack weight showed some relationship with whether a rare card was present in this booster box, but it could not accurately distinguish SAR, SR, AR, RR, and R results.
The measurements published here should be viewed as data collected after fully opening one booster box, not as weight thresholds for selecting “hit packs.”
Summary of the Storm Emeralda Pack Weight Test
After measuring and opening all 30 Japanese Storm Emeralda packs, the main results were:
- The overall measured range was 8.54g–8.67g
- The average pack weight was approximately 8.59g
- The SAR appeared at 8.61g
- The SR appeared at 8.63g
- AR cards appeared at 8.58g and 8.61g
- RR cards appeared between 8.61g and 8.63g
- The heaviest 8.67g pack contained an R
- All seven packs weighing 8.62g or more contained an R or higher rarity
- None of the eight packs weighing 8.57g or less contained an R or higher rarity
- SAR, AR, RR, R, and no-R-or-higher results all appeared at 8.61g
- Higher rarity did not correspond directly to higher pack weight
- No MUR card was observed in this booster box
This booster box showed some tendency for rare cards to appear in relatively heavy packs.
However, the heaviest pack contained an R, while the SAR and AR cards appeared lower in the overall distribution.
Identical displayed weights also produced dramatically different results.
For that reason, pack weight is useful as experimental data for comparing the contents of one booster box, but it cannot be treated as a reliable method for identifying rarity before opening.
This is the tenth pack-weight dataset published on the English version of tekemero.com.
With 10 datasets now available, the next step will be to compare the results across products and look at which patterns appear repeatedly and which disappear when the booster box or product changes.
