I made buttercream with Wal-mart brand powdered sugar. The icing was very greasy feeling. I know it will be greasy feeling since its an all shortening icing.

BUT

I have also made the same buttercream with Dixie Crystals powdered sugar and the icing was less greasy and more fluffy.

I guess a name brand can make a difference.

The thing that made my icing with the WalMart sugar less greasy was that I added cocoa powder to make chocolate and viola the icing go more fluffy and less greasy.

Could it be the quality of sugar and it is ability to absorb the shortening or was it the extra mixing?

What brand sugar do you use?

I use Domino. I've had good luck with this and can usually get it in big bags at BJ's Wholesale club. I also tried the Wal-mart brand and didn't care for it.

If you have a GFS get the commercial grade 6X sugar. It is way better for icing than 10X.

I've read (here on CC) that commercial grade 6X is best. I'll have to see if I can find it. What is a GFS?

I have tried store brands, but they are made from beet sugar and I think that makes a world of difference. I use only Domino because it's pure cane sugar. I'm going to definitely try the 6x now that I've heard about it!

I use Dominos sugar.