How’s the shape of your string?

Is it round, square, hexagonal, octagonal, triangular, or something else?

The string pictured here is square.  The dimension across the flat sides is roughly .048 inches/1.22mm, which means the largest dimension is about .063 inches/1.6mm but due to the rounded edges it is less than that.  The wear is happening on the “flat” side (.048/1.22), 

A flat-sided string shape can create some issues when trying to achieve consistent string tension.  

Side View of Fail

Flat Side Wear

String Bed View

This is expected because the string will want to align with the flat side, not the edges.  This may cause the string to twist and create added friction when tensioning.

So, we can expect the “edges” to be exposed to the ball, and the “edges can create friction on the ball, which causes rotation!  

Yea!  How much and for how long is hard to know.

I believe it is safe to say “square” is a good “shape” for your string to be in for polyester monofilaments which we are looking at here.