A single layer papermakers fabric comprises machine direction (MD) warp yarns interwoven with cross-machine direction (CD) weft yarns to a repeating weave pattern requiring N sheds in the loom, N being an integer and at least 4. Each warp yarn follows a path in the paper side surface comprising four segments in each pattern repeat. In each of the first and third segments, the warp yarn interweaves with three consecutive weft yarns to form a double warp knuckle, and in the second and fourth segments, the warp yarn forms respectively a first and second MD float having unequal float lengths, at least one of the MD floats being over at least N consecutive weft yarns. The fabrics provide high air permeability, and increased surface contact area, stability and seam strength, and are particularly suitable for use as forming fabrics and through air dryer fabrics for tissue and towel products.