A professional who tends machines that twist single strands of silk or synthetic yarn. Responsibilities include:

• Places bobbin in holder and draws yarn from supply package through traverse guide and laps yarn around takeup bobbin.
• Starts machine and observes operation for yarn breaks.
• Pieces up yarn breaks.
• Doffs full packages.
• May fit wire guide onto supply package and thread yarn through guide to retain twist in yarn coming off supply package.