A method for knitting a three-dimensional fabric with variable thickness through a flat knitting machine includes the following steps: moving two cam groups and driving a plurality of knitting needles to knit a first piece of knitting by a starting cam system; moving the two cam groups and driving the plurality of knitting needles to knit a second piece of knitting by a middle cam system; and moving the two cam groups and driving the plurality of knitting needles to knit a supporting yarn by two tail cam systems respectively. The tail cam systems control each of a plurality of knock-over bit cams to move according to a gap size corresponding to a knitting length of the supporting yarn, so as to promptly change a thickness of the three-dimensional fabric along the length change of the supporting yarn.

A method for knitting a three-dimensional fabric with variable thickness through a flat knitting machine includes the following steps: moving two cam groups and driving a plurality of knitting needles to knit a first piece of knitting by a starting cam system; moving the two cam groups and driving the plurality of knitting needles to knit a second piece of knitting by a middle cam system; and moving the two cam groups and driving the plurality of knitting needles to knit a supporting yarn by two tail cam systems respectively. The tail cam systems control each of a plurality of knock-over bit cams to move according to a gap size corresponding to a knitting length of the supporting yarn, so as to promptly change a thickness of the three-dimensional fabric along the length change of the supporting yarn.

A knit fabric having a modified knit structure comprising a first layer of jersey knit fabric and a second layer of jersey knit fabric, wherein the first and second layers of jersey knit fabric are joined to each other by a third layer of tuck stitches, and wherein the first and second jersey stitch layers include at least one continuous strand of bare rubber and a plurality of continuous strands selected from the group consisting of continuous strands of bare rubber and continuous strands of non-elastic yarn, and the third layer of tuck stitches are made of continuous strands of non-elastic yarn, knit together into the fabric so as to hold the first and second jersey stitch layers together.