I like Cretan anyway, so adding the knot wasn't a problem and adds lots of texture. The green is done in perle cotton #8 with the right side showing more than one knot on each stitch.
The yellow it to show how they can nest. The right side is done wonky.
The orange is a heavier thread called Isabella. It was in my stash, so I don't know if it is even still available. The next row shows it with the perle done over it.
Time was short this week, so it's just a simple example.