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Please refer to ITTF Tech Leaflet T4 for information on pip dimension limits
The table below shows some ample calculations based on pre-1999 & post 1998 (current) ITTF specification but proposed fair values for a level playing field (to promote spectator presentation)
Please read my detailed explanation & discussions of these parameters in posts below by me & others

Is there some significance to values shown here for length , width and aspect ratio ?
Why does ITTF use Aspect Ratio of 0.89 as the divider between long pips and short pips , for instance ?

Karl Spin wrote: ↑August 25th, 2023, 1:50 am Is there some significance to values shown here for length , width and aspect ratio ?
Why does ITTF use Aspect Ratio of 0.89 as the divider between long pips and short pips , for instance ?

Below are some details from Section 2 of ITTF Tech Leaflet T4 that was posted before by Caroline W

I chose the values as shown in my first post, using maximum & minimum values of the 3 parameters , height, diameter & aspect ratio to provide insights into design and behaviors of pips rubbers.
The calculations were made for the third parameter using minimum or maximum values for other two parameters allowed by ITTF. The three parameters are Pip Height, Pip Diameter & Aspect Ratio , which is Pip height divided by pip diameter

ITTF "regulations" in tech leaflet T4 says the maximum aspect ratio allowed for short pips is 0.89 & width cannot exceed 2.2 mm, this means the length can be upto 1.96 mm. But the ITTF rule 2.4.3 says the "thickness' cannot exceed 2.0 mm . the 2.0 mm is inclding the base thickness & glue. So from a practical stand point the the maximum pip length cannot be more than 1.8 mm if you allow only 0.1 mm each for base & thickness.

However the key here is that this 1.8 mm maximum length applies to both long pips as well as short pips rubbers, because strangely ITTF differentiates long pips from short pips not based on length of the pips but based on just aspect ratio only. That can be termed bizarre because then the short pipe can be just as long as long pips rubbers.
Then what really is the difference between short pips & long pips ? One has to conclude that it has to some other pip design parameters other than pip height of 1.8 mm.
So this is why the long pips are "seemingly" "long" compared to short pips because they have lower width compared to short pips.
Another key differentiator is pip flexibility & pip hardness. The long pips are more flexible but short pips are more stiffer in general.
All Curl P1 versions are softer (more deception & lesser control) & al Feint Long versions are little harder (less deception & more control)
Feint Long has a bit more back spin because the aspect ratio is at the limits.
Of course both Feint Long 3 & Curl & all other ITTF LARC rubbers are totally useless for defenders in the 40+ plastic ball era but that is entirely seperate issue that became relevant afterwards starting with 40- celluloid ball of 2000 and 2004 PDD regulation & 40+ plastic ball of 2014

This could also explain the reason why neo short pips can be made to behave just like long pips. Because they obviously can be just as long if you lower the pip width , as long you keep the aspect ratio below 0.89 to qualify it as short pips. This is also why manufacturers can also claim that their revolutionary short pips are great cchopping tools.

Another reason why the difference in behavior of short pips & long pips has become more closer to each other (this is what ITTF wanted, to oppress the choppers) is because the maximum allowed aspect ratio was lowered by ITTF from 1.3 to 1.i in 1998, which would mean the long pips have to more wider to meet the maximum allowed length of 2.0 mm (remains same) but lowered aspect ratio. So this lowers the back spin production capability of long pips as well as lowering the looper torture index, which again is also what the robotNazi controlled ITTF wanted whie lowering the aspect ratio from 1.3 to 1.1 in 1998 in the Durban mAssacre.

How many pips players even understand what "Aspect Ratio" is as related to pips , let alone its horrible ramifications

In Column 3 of Caroline w 's chart the pip height is 1.96 mm, almost at the maximum of 2.0 mm for any pips, short or long.

So it seems to me that this is how manufacturere are able to design short pips that behave almost identical to long pips.
If the pips are also made flexible & with material like TSP P1 Curl , it makes the short pips even more identical to long pips.
Pretty clever on the part of manufacturers