egress 8 and the yarn guide 23 for each revolution of the rotor a yarn guide 35 is provided below the spindle station for use when spinning singles yarn in practice when yarns 31 and 32 are processed together real plying twist is generated between them by virtue of yarn 31 being ballooned around the supply package 20 this plying twist is inserted at the yarn guide 23 to form a plied yarn 34 and is carried downstream with the yarn 34 from that point in practice it has been found that by virtue of the plying torque generated at the yarn guide 23 the plying twist also tends to run against the flow of yarn some way towards the yarn egress 8 from the yarn guide 23 the plied yarn 34 is delivered via the take off rollers 24 and the drafting rollers 28 to the yarn take up station 29 if this plied yarn is now examined and the plying twist is removed by untwisting it will be found that the two singles yarn components both contain twists which are equal in magnitude and sense and are equal in magnitude but of opposite sense to the plying twist between them this yarn structure is thus identical with a two fold yarn of conventional manufacture in which firstly singles yarns are spun having x twists per unit length of z twist and two such singles yarn are plied together with x twists per unit length of s twist referring now to fig2 when it is desired to produce a singles yarn the lower supply package.