This is a 2x1 needle arrangement for a 2x2 rib. I wanted the buttonholes to be 4 stitches wide. The stitches marked in red will be the buttonhole.
To make the buttonhole I chained off 4 stitches, then e-wrapped those empty needles, then continued with the ribbed band. The arrow shows the transfer of the stitches. I like the buttonhole to be symmetrical on the rib, therefore moved the 2 middle stitches from one bed, 1 stich on each side from the other bed.
Step by step explanation: Stitch on needle #36 on main bed is transferred to ribber needle #37. Needle 37 on ribber has now two stitches.
Now I took a new piece of yarn, put it in the needle hook and knitted through.
New stitch is knitted on ribber #37.
I then continued moved ribber #37 to ribber #38, knitted through with same loose piece of yarn, then transferred ribber #38 to mainbed #38, again knitted through, then to mainbed #39. I now have 4 empty needles which are chained off.
Next Step: Those 4 empty needles get e-wrapped. The 2 loose yarn ends need to be pulled through the beds.
Here the yarn ends are pulled through the beds and weighted with a cloth pin.
After having done all the buttonholes in the band, I pulled out the needles over the buttonholes. There is no weight on the e-wrapped stitches, and pulled out, they knit much better. I did the pulling out for several rows.
This is the look the buttonhole comes off the machine. Now I just had to finish the loose ends. And here it is:
And here is the finished cardigan with a pretty buttonhole band on 2x2 rib.