Roundwound Strings
This is the most popular variation. A continuous length of round wire wraps an inner core of steel. Actually, a machine spins the core and the attached wire builds up in one continuous layer around the spinning core.

Flatwound Strings
A continuous length of ribbon-like stainless steel is wrapped round a stainless steel core. Flatwound strings reduce the finger-generated noise produced by roundwound strings. They also produce a more mellow tone.

Groundwound Strings
This is an attempt to combine the properties of the flatwound and the roundwound strings. These strings project a bright tone with sustain and a soft feel.