These two scarves don't look it, but they are both made using my favourite fancy rib.
Every row: K3P1 to last st which is K1
Knitted using average size needles for the yarn gives the result on the left (DK yarn and 4mm needles in this case.) It is a very stable, tight rib, which does not spread in wear.
But if you use much larger needles than normal (in the case of the green version, two strands of fine laceweight yarn and 4.5mm needles), you can block the result into a much wider, more relaxed fabric that looks very different.
I had some left over Manos de Uruguay Lace yarn left over and used it two strands at a time to make this wide, light scarf to keep my shoulders and upper back warm.
One of the joys of knitting is that you can make the same stitch do such very different things!