powdered sugar question

What is the difference between 4X powdered sugar and 10X powdered sugar? The powdered sugar I buy doesn’t specify. Also, if a recipe specifically asks for one or the other, can I use whatever I have? (whatever it may be?)

The “X”'s refer to the fineness of the sugar; the more “X”'s there are the finer the sugar is. I use whatever I have and never have a problem with it.

KW, again, thanks for your knowledge. Is there a way to make powdered sugar? Probably a lot of work, but curious. Also, do you have any idea what the purpose of corn starch is in powdered sugar? Does it just keep it from clumping?? Just wondering…thanks!

Thanks for your immediate reply. I’m still fairly new here so haven’t discovered al the secrets, but I’m working on checking more sites all the time. Thanks again.