Multi-layer papermaker's forming fabric with auxiliary bottom MD yarns

A papermaker's fabric, comprising a series of repeat units, each of the repeat units comprising:

• a set of top machine direction (MD) yarns having a first diameter;
• a set of bottom MD yarns having a second diameter larger than the first diameter;
• a set of auxiliary bottom MD yarns having the first diameter;
• a set of top cross machine direction (CMD) yarns interwoven with the top MD yarns to form a top fabric layer;
• a set of bottom CMD yarns interwoven with the bottom MD yarns and the auxiliary bottom MD yarns to form a bottom fabric layer;
• and
• a set of stitching yarns arranged in pairs, wherein at least one of the stitching yarns of the pair interweaves with the top and bottom fabric layers;
• wherein each of the auxiliary bottom MD yarns is interwoven with the bottom CMD yarns such that it forms a knuckle under bottom CMD yarns under which the adjacent bottom MD yarns also form knuckles.