How to make material more transparent in stretched spots

Hi,
I want to make a material which looks like stockings/tights, where the material becomes more transparent in the spots which stretch the mesh more. How could I go about achieving this effect?
Untitled

I was thinking an alpha map would do it, but I was hoping there was a way which does not need to be drawn on by hand.
Here is my node setup currently

Use a colorramp between your image that you have and your alpha socket, and play around with the black and white values