How to get capacitive touch threshold values

[Vishnu_C]

Hello members, I need help with capacitive touch button. I m using esp32 S3 & spring to detect touch. There is an over lay approximate thickness of overlay(plastic) is 4mm. I uploaded the example "TOUCH READ" sketch from arduino ide and got these values -> 36000 (not sensed) & 38000 (when sensed). After this uploaded "Touch button V2" from example and changed threshold value to around 37500 but the controller didn't sense the touch though value was above 37500 and I printed on serial monitor. It sensed only when I directly touch the spring with my bare hands. After many trials with different materials as over lay I didn't find any results and just changed threshold value to approx 1500 and this time esp32 detected the touch with over lay . Can anyone explain whether I need to add threshold value 37500 or 1500 because I came across an YouTube video the hobbyist mentioned to use the value which we get when touched so I got around 38000 and I started with 37500 , did so many changes but never worked but as I changed it to 1500 it worked (can say difference between touched & not touched values) and is this the right way of getting threshold values. I really appreciate any help me to learn . Thank you