Help How to reduce thickness in cloth self-collison?

[xxxh123]

Hi! I am trying to fold a cloth mesh (i.e. T shirt) using self-collision on a table-top scene, but I find that the thickness of the cloth is too high when it is folded many times. How can I reduce the thickness of cloth under particle self-collision just like this? 

I have tried to reduce the radius of particles in the blueprint, but that often leads to penetration between two surfaces.