To facilitate positioning of the hoop on these lines, I have used strips of Wonder Tape on the inner wrong side of the hoop. In this way, when I press the inner hoop into position, the tape will prevent the inner hoop from moving when I insert it into the outer hoop.
The larger the hoop, the longer the sides. With our home embroidery machine hoops, these longer sides tend to pull away from the outer hoop as we tighten. To see this for yourself, grab a large hoop, lay it on a flat surface and begin tightening the screw. Pay special attention to the side furthest away from the screw. You'll notice that the long sides pull inward, away from the outer hoop, leaving a gap. When sewing on heavier fabrics, the fabric will take up the gap, but on lighter weight fabrics, this gap can cause your project to slip as the design stitches.
Even with a hoop with a center screw, these long sides tend to pull away from the outer hoop. It isn't any one brand - it's just the nature of physics!
Wonder Tape on the inner hoop really helps to prevent the fabric from slipping and in many cases is enough. You do not need to replace the Wonder Tape for each hooping; I find it lasts through about 6 hoopings, depending on the fabric. When it is no longer sticky enough to do its job, simply run your hoop under water to remove it. It's really great to have two hoops if you can manage it.
I use a product called Fusi-Batt on most of my Embroidery Library projects. The Fusi-Batt is quite tightly woven and has enough grip and stability that I find coupled with Wonder Tape gives me a good hooping. But there are times when I don't want the heavier batting behind my design, which leaves me with a bit of a quandary.
Joan Warr came up with an excellent idea for hooping lightweight fabrics, including water-soluble stabilizers that are either too thin or too slippery to be gripped tightly in the hoop. She uses rubber gripper that she attaches to the inner hoop with Wonder Tape. Rubber gripper can be purchased at Wal-Mart and just about any hardware store. It comes in a roll and its 'normal' use is for lining kitchen cupboards to prevent your dishes from slipping.