M1 vs Kf/b

Samm (from the comments) asked for an explanation as to why you cannot use a M1 and a Kf/b interchangeably. So here we go.

A M1 is an increase which uses the horizontal bar or running thread between 2 stitches to make a new stitch.

M1– Make 1 stitch: With Left needle, lift the running thread between the stitch just worked and the next stitch, from front to back, and knit into the back of the resulting loop.

And a Kf/b (see below) uses 1 knit stitch to make a new knit stitch so that this 1 stitch becomes 2 stitches.

Kf/b: Increase of 1 stitch: Knit into the front of the next stitch as usual and without taking the stitch off the left needle, knit into the back of the same stitch.

They are both excellent increases. The Kf/b is easier to work and has a ton of applications. The problem with it is that it is not symmetrical. When you make the second stitch by knitting into the back of the stitch you produce a knit stitch and then a stitch with a bar across it. It's terrific if you are fitting it into ribbing because the second stitch mimics a purl stitch. This barred stitch is always to the left of the knit stitch. When doing increases for a top down garment I prefer the M1 because I don't get that second barred stitch. You can make the M1 stitch symmetrical so that it leans to the right or left.

My favourite is what I call the Open M1 which has no lean and doesn't make you stop in your tracks while you are knitting.

OPEN M1: (makes a small hole) Insert Right needle under the running thread between the stitch just worked and next stitch without lifting or twisting it, wrap wool around needle and complete as a normal knit stitch (similar to a pick up & knit).
It makes a small hole but it's not fiddly because it's just another knit stitch except under the horizontal bar instead of into a stitch on the needle.

Now, all that said I like all of these increases. The problem arises if you try to use a Kf/b when the instructions say to use a M1 increase. Example: If you have a section of 4 stitches and you are to work 2 increases written as: K1, M1, K2, M1, K1. You would knit 1 stitch, work the M1 increase between stitch#1 and stitch#2, knit stitch#2 and stitch#3, work the M1 increase after stitch#3, Knit stitch#4. Now you have 6 sts.

Here it is with the Open M1 with the little holes.

If you work the Kf/b increase instead of the M1 then you would knit 1 stitch, work into the front and back of stitch#2, knit 2 more sts (stitch#3 & stitch#4) and now you have run out of stitches and only increased 1 stitch. The increase is after stitch#3 instead of after stitch#2.

If you are very familiar with how these 2 increases work and want to use the Kf/b instead of the M1, you would write it as: Kf/b, K1, Kf/b, K1. Looks really different written down but gives you exactly the same result because the Kf part is a knit stitch and the b is the increase. I have NO problem if you can do the rewrite, none, nada. The problem is substituting one for the other without giving it some thought.Ahh, correct and lovely.

School is over. Was that a lecture or what?! Do you feel like you were sitting in a little tiny desk? You may all go out for recess now. No throwing snowballs and look out for the little kids on the playground. The knitting club will meet in the lunch room. You know where I'll be, out throwing snowballs, ha, ha.

-Deb