What is the best sugar for sweet short crust pastry? I am reading an American Pastry &amp; Pies cookbook and they say the sugar granules in sweet short crust pastry stabilize it and recommend using granulated sugar. So does this mean the bigger the sugar grains the better?  I assume there would be a limit to how big you want to use.  I am half American and using my experience of sugar in both countries I will grade what is available here and the US in grain size to help answer the question.

powered sugar/ icing mix - white powder

confectioners sugar / castor sugar - like very fine white sand with tiny separate grains

brown sugar* not raw sugar - small sticky brown grains

granulated sugar - unified small individual white grains

white sugar - cane sugar, most similar to granulated sugar but grains can vary in size and shape depending on brand and processing - white

Raw sugar - large translucent brown individual grains (I have never seen this available in supermarkets in the US and when Australians say brown sugar in their tea/coffee they usually mean raw sugar*)

coffee sugar - big dark brown translucent 3-5mm cubes.

Thank you.
Granulated to caster ie: fine sugar is the most recommended. I use caster sugar to get a smooth transition in the pastry. Then chill at least 20 minutes before baking to relax the gluten so it is nice and flaky.