I don't remember the needle size either, most probably 3 mms.
Unlike the Yarn harlot I did buttonholes all the way. Recently I've done things that buttons only partially, but this time I would like to be able to control just how many buttons I am closing.
BTW simple, but thicker than usual mother of pearl buttons.
Great pattern. I am already thinking doing it from a different color... maybe with long sleeves?