What is the difference when a powdered sugar says its 2X versus a 10X?

Does it have to do with the fineness of it and would it make the icing smoother or what?

I have been using a 10X that I had bought in a 7lb bag.

You should definitely use 10X. It is a finer sugar. One of my students made a mistake and used 2x and she couldn't even get the icing through any of the tips. Sometimes when you make a mistake you learn from it and she is sold on 10x now.

10X is finer... like it's sifted more.. I always use 10X. You normally don't have to sift it at all.

Here is the scoop, it has to do with the original processing of the sugar. 10X sugar is processed by being passed through a screen or sieve - it is a wire mesh of a 10X gauge which is a fine screen meaning that the holes are very small. 2X would be processed by being passed through a less fine mesh or screen. This results in 10X sugar being of a much finer particle. The finer the particles, the easier it is to incorporate the sugar into the shortening or butter. Less grit.
Hugs Squirrelly Cakes

Meant to add this, another thing that may cause issues is the difference between cane sugar and beet sugar. Both have the same sweetening power. The issue seems to be more of a processing issue. For some reason, it appears that beet sugar seems more susceptible to picking up moisture, likely has something to do with the processing. Both kinds of of powdered or icing sugar have cornstarch added to them (in Canada and the U.S.) to aid in the clumping issue. However clumping tends to be more of an issue with the beet sugar.
Regardless, over time or with high humidity levels, even 10X sugar can develop clumps which is why I always sift the sugar before measuring it or using it. If you use clumpy sugar in a cooked icing recipe, the clumps will not dissolve. Sometimes they will not dissolve in a regular buttercream icing recipe either.

Where on the package will it say 10X or 2X?
~~Connie

In Canada, it generally just says confectioners or icing sugar here.
Hugs Squirrelly Cakes

Confectioners and icing sugar is 10X?
~~Connie

Gee I have been sheltered being here.... I didnt know there was 2x sugar..... cool!!!!!

Thank you squirrly cakes for giving me the lowdown on the difference.

I didn't really know that there was a difference until someone I was talking to said to make sure you use a powdered sugar that was __X. So, when I got home I looked on my bag and it says on the front 10X and wondered.

I don't know if anybody has tried store brand powder sugar. But I've tried both (store and name) and name brand works the best in my opinion. I don't know if I can say name brands or not but the one I like is same name of a game where you line up blocks in a row and know them down. Or you could actually play it as originally designed.

10X = sifted 10 times....

I've got two different brands here, one has a crown on it (made in Texas), and it very plainly says 10X on it, and then I've got one that has a boy in their advertising, and it doesn't say what X it is! I saw on the package a 10 and bought it, and now looking at it, the 10 is 10 calories per serving! I have bought this before and it worked ok, but I'd prefer to know what the fineness is.

This is funny, the 2 lbs of the crown one feels heavier and firmer than the 2 lbs of the boy kind, maybe that's where some of our differences are, we may have to measure to be sure in our recipes! Janice

Yes, the 10X doesn't mean sifted ten times or the 2x twice, it does mean that the fineness of the mesh or sieve that the sugar is originally processed through was 10 or 2 gauge, the 10 being finer.
In Canada they do not grade the Canadian sugar that way, it just says icing or confectioner's sugar on the bag, that is what I meant that there is no way to tell. Up until about a year ago, all of the icing sugar or powdered sugar sold here was cane sugar but now Rogers in Western Canada is processing beet sugar into icing sugar and our sugar no longer states 100% Pure Cane Sugar, so it could be either.
I am a firm believer in sticking with a good name brand that you have found you can trust.
I am also a firm believer in always sifting the icing sugar first, before measuring it as some times it does settle. I sometimes haven't taken the time to sift it and I can really feel a difference in the icing, not that it is gritty, but just not as smooth.
I would guess that in the U.S. unless it says 10X, it likely isn't.
Hugs Squirrelly Cakes

I like the name brand over the store brand, different in texture, but sometimes I have to use the store brand cause the name brand is sold out. When I sift the store brand it tends to makes it way on the counter, floor and even outside of the bowl. However, it does not happen to the name brand at least not as much as the store brand. So much gets wasted when it lands on the floor and even on the counter, what a mess I have made is usually what I say to myself.

Heehee, 2 cakes, welcome to the official "Inhaling Icing Sugar Club"! Now if it isn't in your lungs and on the counter, the cupboards, in the drawers, on the floor - if you do not have a fine white dust from one end of the kitchen to the other, well then you are not really a cake decorator! See that is what makes our dispositions so sweet, ok, it only works on some of us, haha! But, congratulations kiddo, you are in the big league now!
Icing sugar has so much static in it and when you sift it, well it is even worse. It doesn't matter how careful I am, it always gets everywhere. I swear I have sweet dust!
I wash the floor before I do a cake and afterwards. I bleach down the counter and the sink before and after too. Heck, it is like cooking a turkey, bleach, bleach, bleach.
That is the worst part of baking and decorating, the clean-up! Geesh, if only we all had assistants!
Hugs Squirrelly Cakes

HI SquirrellyCakes! Yes, it would be nice if we had an assistant at least for the before and after cleaning and run errands for some of the baking items when you are completely out of them. But as for the baking and decorating the cakes, I know that we would like to do them ourselves. Have a great day.