To prepare the classic idlis, two parts uncooked rice to one part split urad dal are soaked until they can be ground to a paste in a heavy grinding stone vessel, the attu kal.

And this man is still making the traditional granit mortar and the flat stone to roll the dosai with this heavy granit rolling pin used by so many women in the kitchen still.

I posted earlier a woman making idli with the granit vessel you can see here.