From their website:
Assembly of 2 strands of moderate shine.
Au Ver à Soie Surfine™ is an assembly of 2 strands of moderate brilliance, made from schappe silk (combed silk), it is perfect for all uses in the field of needlework, available in an inimitable range of more than 210 colors in 300m coil.
In 1890, the Surfine™ Silk card had 2688 different colors divided into 107 ranges. It is this card that serves as a reference to add new colors.