There are several common ways to perform the “make one” increase you will see in knitting patterns. To make one is to increase by a single stitch. Depending on the pattern you may be asked to do it several times in a row, or once at each end of a row.
They are not interchangeable, and knowing the difference is worth the few minutes it takes.
Make one (M1)
The most common. You lift the horizontal strand running between two stitches onto the left needle and knit into it.
The critical part is knitting into the back of that lifted strand. If you knit into the front, you create a hole – which is either a mistake or a design feature depending on what the pattern wanted.
M1 is nearly invisible when done correctly, which is why it is the default for shaping garments where you do not want the increases to show.
It comes in left-leaning and right-leaning versions (M1L and M1R), which differ only in which direction you lift the strand. Patterns use both so shaping is symmetrical on either side of a garment.
Yarn over (yo)
Simply wrapping the yarn around the needle to create a new loop.
This deliberately creates a hole. That makes it the wrong choice for invisible shaping and exactly the right choice for lace, where the holes are the design.
It is also the easiest increase to work, which is why beginners sometimes use it where M1 was intended and then wonder about the eyelets.
Bar increase (kfb)
Knit into the front of a stitch, then, without dropping it, knit into the back of the same stitch. Two stitches from one.
It leaves a small horizontal bar at the base of the new stitch – visible, which is the trade-off. In garter stitch or a textured fabric it disappears; in smooth stocking stitch it shows as a row of little dashes.
It is the simplest increase to work reliably and it is very secure, which makes it a good choice for beginners and for places where the bar will not be seen.
Lifted increase
Knitting into the stitch below the next stitch on the needle. Nearly invisible and very neat, and slightly fiddlier than M1.
Which to use
Use what the pattern specifies – the designer chose it for a reason, usually to do with whether the increase should show.
If you are improvising: M1 for invisible garment shaping, yarn over for lace, kfb for anything where a small bar will not matter.
And if a pattern says only “increase”, kfb is the traditional default.
