"Virtual fineness" - Proposal for the indication of the fineness of conductive yarns

Conductive yarns contain metallic materials, alongside textile materials such as cotton, polyester, etc., in order to provide the minimum conductivity that is requested in diverse applications in the field of technical textiles. Yarns are commonly classified by their fineness; however, tis can be misleading whenever a metallic material is embedded in a yarn to provide the desired electrical conductivity. A misinterpretation can occur due to the density of metal which strongly influences the total mass of the yarn. Therefore, we suggest a new criterion that we call "virtual fineness" which can be derived under the computational assumption that the metal in a yarn is substituted by the same textile material which is used in the yarn.