Pizza dough with sand paper texture? Every time I have had a really good pizza (usually in Italy for some reason) there's one thing that stand out more than anything else and that's the crust. What I have noticed about those really good pizzas is that the crust have a very rough texture, almost like sand paper. I have tried to find a picture of this but it's hard to find any. This was the best I could find now:



You see all those white spots? (They are all over the pizza, not only on the bottom like in this picture) What are they and why do only a few pizzas have them? Is it a special kind of flour in the dough? Is it some other secret ingredient? Every time I see a pizza with this texture I know it will be a good one. Note: It's not just dusted with flour. It seem to be embedded and part of the dough.
Oftentimes, semolina is spread on the peel so that the pizza will slide off (known as launching).  That could cause this phenomenon.