Plus sized half slips come in virtually any length, from 14"" mini to 27"" below-the-knee lengths. They are available in many styles, too. Some plus-size slips function more like shapewear, using compression to smooth and slim and silicone gripper to keep the slip in place.
For sheer skirts or those with a looser line, half slips with gently gathered waists and an a-line shape will be most comfortable. For versatility, look for a slip with a slit that can be worn on the side, in the front or in the back. Plus-size half slips range in size to a 3XL, which fits a 36-37"" waist and hips of 51"" or more.