Warchal describes the Amber Strings as follows:
"The Amber set has been developed with the aim of achieving the sound quality of the best gut strings without any tuning instabilities. The set features W-Core®, a completely new core material developed by our Research & Development team.
The sound is rich and warm, but still has texture. The strings also feature a distinctive high quality silking design.
The Amber E string is based on our newest unique invention. Our solution increases the longitudinal elasticity of the string, which results in a significant sound improvement and no whistling.
*E-ball IFT is suitable for integrated fine tuner tailpiece"