Hello again Ben,
Could you be a little more specific about the stranded conductors you are interested in re skin effect?
A) - Large Conductor Power Cable - Concentrically Stranded or to the standard Milliken design.

- Concentrically Stranded Conductor Audio Cable to say 20 kHz.
C) - Data Cables with concentrically stranded conductors.
D) - Radio Frequency Cables with concentrically stranded inner conductors.
E) - Other, please elaborate.
Thank you.
Kindest regards,
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com