KFB stands for "knit into the front, and then the back of the same stitch," and is sometimes abbreviated
- k 1 f, b (knit 1 front, back) or
- k f/b (knit front/back) or simply
- kfb (knit front back)
As you can guess, knitting twice into the same foundation stitch causes this one foundation stitch give birth to two new daughter stitches, which is how this trick comes to be an increase.
Here is the how-to:
1. (below) This is the "before" picture of the foundation stitch into which you will kfb. In the illustration, the front of the foundation stitch (the right arm, which lays forward on the needle) is blue, while the back of the foundation stitch (the left arm, which lays behind the needle) is green. The running yarn--which will become the first part of the kfb--is pink.
2. (below) The pink running yarn has been knitted in the regular knitting way, and now lays as a loop on the right needle. Note that the foundation stitch (half green and half blue) has not been slid off the left needle. In other words, even though you have already knitted into the foundation stitch, you have only done the first half of the operation (the knitting into the front of the stitch) and therefore, the kfb stitch must remain on the left needle for the second half of the operation.
3. (below) The next step will be to knit into the back arm (the green arm) of the foundation stitch. The red arrow shows the path the needle must take. Specifically, you must swing the needle around to the back of the work, then down through the left arm of the foundation stitch, as shown by the arrow.
4. (below) As you see, swinging the right needle down and through the back (green) arm of the foundation stitch has twisted the foundation stitch into a figure "8," with the right needle through the TOP part of the stitch. Note that the bottom part of the foundation stitch is not twisted, only the top part of the stitch.
Once you have the needle through the top of the foundation loop, the next step is to pull through the running yarn (now colored purple).
5. (below) Here is the finished kfb with the purple running yarn drawn as a loop though the back (green) arm of the foundation stitch.
As you can see, the (pink) stitch through the front (blue) of the foundation stitch is drawn though the untwisted bottom part of the foundation stitch, while the (purple) stitch drawn though the back (green) arm of the foundation stitch is drawn through the twisted top portion of the foundation stitch--the twist having been made back in steps 3 and 4 when the right needle was inserted for the second time into the foundation stitch.
6 and 7. (below) Kfb has a reputation as an amateurish sort of an increase, but this reputation is undeserved. A regular series of kfb's looks very well, as the two final illustrations show.
--TECHknitter
You have been reading TECHknitting on "knit into the front, knit into the back, abbreviated k1 fb or k f/b or kfb"