In the previous test, I measured a second booster box of The Glory of Team Rocket and compared its pack-weight distribution with my first test of the same Japanese product.
This time, I tested Inferno X.
Inferno X is a Japanese MEGA Series expansion released in Japan on September 26, 2025. Each standard booster pack contains five cards.
Many cards from the Japanese Inferno X set were later included in the English Mega Evolution—Phantasmal Flames expansion.
This article focuses specifically on the original Japanese Inferno X booster packs.
For this experiment, I used all 30 packs from an unopened 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 SR, AR, RR, and R cards.
The overall result showed some noticeable tendencies.
The SR in this booster box appeared in the heaviest pack.
RR cards were also concentrated mainly toward the heavier end of the measured range.
However, the weight ranges of AR, RR, and R cards overlapped, with some packs differing by only 0.01g to 0.02g.
Therefore:
Although some relationship between weight and rarity was visible 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 also be affected by the foil wrapper, card finishes, 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.
Test Conditions
The test was conducted under the following conditions.
- Product: Japanese Inferno X 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
- Temperature and humidity were not strictly controlled
- All 30 packs were opened after weighing
- 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.
There may also be small differences in printing, surface treatments, card cutting, and other manufacturing characteristics.
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.
Inferno X Pack Weight Results: 30 Packs Measured
The overall differences between packs in this booster box were relatively small.
Many packs produced measurements very close to one another.
The SR was found in the heaviest pack of the booster box.
RR cards were mainly concentrated at approximately 8.64g or above.
AR cards were primarily observed around 8.58g–8.63g.
R cards appeared mainly around 8.56g–8.61g.
Although some rarity-related tendencies were visible, the individual weight ranges were not completely separated.
What the Measurements Showed
The main findings from these 30 packs were:
- The SR was found in the heaviest pack of the booster box
- RR cards were mainly found around 8.64g or above
- AR cards were mainly found around 8.58g–8.63g
- R cards were mainly found around 8.56g–8.61g
- The AR, RR, and R weight ranges partially overlapped
- Many packs differed by only around 0.01g
In this booster box, the SR and several RR cards appeared toward the heavier end of the distribution.
However, neighboring weight measurements often produced different rarity results.
For that reason, the numbers alone could not be used to accurately predict what was inside an unopened pack.
SR Pack Weight
The SR observed in this test came from the heaviest pack among all 30 measured.
Looking at this result alone, it is possible that the surface treatment of the SR or the overall combination of cards inside the pack contributed to a slightly higher total weight.
However, only a limited number of SR cards were observed in this booster box.
One booster box is not enough to establish a repeatable weight pattern.
The position of an SR pack within another box could also change because of differences in the wrapper or the other cards inside.
The only conclusion supported by this test is:
In this booster box, the SR was found in the heaviest measured pack.
This does not mean that the heaviest Inferno X pack will always contain an SR or that packs above a certain weight can reliably be identified as SR packs.
No MUR card was observed in this booster box.
Because I do not have an actual MUR measurement from this test, I cannot determine whether an MUR pack would be heavier than the other rarity levels.
AR Pack Weight
AR cards were mainly observed around 8.58g–8.63g.
They tended to appear closer to the middle of the overall distribution than the SR and heavier RR packs.
However, the same general range also contained R and RR results.
There was therefore no weight range unique to AR cards.
The overall differences between packs were also small.
In some cases, neighboring packs differed by only around 0.01g.
A difference this small may be affected by packaging material, individual card variation, the measuring surface, vibration, humidity, or the scale itself.
Based on these results, AR packs could not be accurately identified using weight alone.
RR Pack Weight
RR cards were mainly found toward the heavier end of the distribution, particularly around 8.64g or above.
Several RR results appeared around approximately 8.65g–8.67g.
Within this particular booster box, RR cards therefore showed a tendency to appear in relatively heavy packs.
However, the RR and AR ranges were close to one another and were not completely separated.
The foil wrapper and the other cards inside each pack can also affect the final weight.
Therefore:
A pack weighing 8.64g or more should not be assumed to contain an RR, and a heavy pack should not automatically be considered an RR pack.
These numbers represent only the packs measured within this specific booster box.
R Pack Weight
R cards were mainly observed from approximately 8.56g to 8.61g.
Overall, they appeared toward the lighter side of the distribution.
However, some measurements were close to those of AR packs.
This means that a relatively light pack could not automatically be identified as an R pack.
The distribution may also shift in another booster box because of differences in the cards or packaging.
Results by Weight Range
The opening results from this booster box can be grouped into several approximate ranges.
✅Around 8.56g: Mainly R cards
Many of the lighter packs in this booster box produced R results.
However, this does not mean that every light Inferno X pack will contain only an R or a standard configuration.
✅Around 8.58g–8.63g: AR, R, and RR results overlapped
This was the range with the greatest amount of overlap.
Several AR cards appeared here, but R and RR results were also present.
There was no clear boundary that allowed one rarity to be separated from another using weight alone.
✅Around 8.64g and above: RR and SR appeared
In this booster box, the heavier range contained several RR cards as well as the SR.
However, these results apply only to these 30 packs.
This range should not be treated as a guarantee of a higher-rarity card.
Why Do Different Rarities Overlap in Weight?
The rarity ranges in this test were not completely separated.
Several factors may contribute to that overlap.
- Differences in foil-wrapper thickness or sealing
- Printing coverage and surface treatment of individual cards
- Card-cutting and manufacturing variation
- The combination of other cards inside the pack
- Digital-scale measurement resolution
- Surface stability, vibration, airflow, and humidity
Even if a higher-rarity card adds a small amount of weight, that difference may be reduced or offset by variations in the packaging and the other cards.
The opposite can also occur.
A standard pack configuration could potentially weigh slightly more because of those same variables.
Can Japanese Inferno X Packs Be Weighed to Identify Rarity?
This booster box showed a noticeable tendency for the SR and several RR cards to appear toward the heavier end.
However, the complete dataset also showed:
- AR, RR, and R weight ranges were close to one another
- Several different rarities appeared within the middle weight range
- Many packs differed by only around 0.01g
- Factors other than card rarity can affect total pack weight
- This experiment used only one booster box and 30 packs
Based on these results, pack weight showed some relationship with rarity within this booster box, but it could not accurately distinguish SR, AR, RR, and R packs.
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 Inferno X Pack Weight Test
After measuring and opening all 30 Japanese Inferno X packs, the main results were:
- The SR appeared in the heaviest pack of the booster box
- RR cards were mainly found around 8.64g or above
- AR cards were mainly found around 8.58g–8.63g
- R cards were mainly found around 8.56g–8.61g
- The AR, RR, and R weight ranges partially overlapped
- The overall differences between packs were small
- Pack weight alone could not accurately identify rarity
The SR and several RR cards were found toward the heavier side of this booster box.
However, the individual rarity ranges were not completely separated, and different opening results appeared at very similar weights.
This experiment also covers only one booster box.
Another Inferno X box may produce a different overall distribution because of differences in card combinations, packaging, or production conditions.
No MUR card was observed in this booster box.
If an MUR appears in a future Inferno X test, I plan to record its weight and compare it directly with the SR, AR, RR, and R results.
This is the seventh pack-weight dataset published on the English version of tekemero.com.
I will continue measuring additional Japanese booster products under the same conditions and comparing whether similar patterns appear across different sets and booster boxes.
