Currently, Energizers, Silks Desire, and Silks, are all manufactured by Doris Hosiery. They were once manufactured by Phantom, but Phantom sold off the hosiery division to Doris in January 2011.
There are still pairs of hosiery sold in some stores. You should be able to tell which company made it, simply by looking for the Phantom name on the back. Also, Phantom used 4 digit style numbers, and Doris uses 5 digit numbers. Typically, Doris makes the hosiery slimmer and longer than Phantom did.