That makes as much sense to me as some of the stuff on the software forumtoggle said:ok.
the maths goes like this....
in garter stitch, the width of 2 rows is almost equal to one stitch. in stocking stitch, 2 rows is equal to about 1.4 times the width of each stitch. so bias or mitred squares with a 1 stitch per row increase have to be garter to be square. A few rows of stocking stitch won't do much, that will block out, but too much, gives you diamonds, yeah.
I've got a garter stitch bias with a raised leaf in one corner that looks good.