I bought a set of three fabric resistance bands last month for fifteen dollars. The cardboard box claimed they were anti-slip and would never roll up during a workout. That part is technically true. They do not roll up like the thin rubber loops do. But the heaviest band in the set is so stiff I cannot actually move my legs apart when I put it on.
I tried doing lateral side steps across my living room on Tuesday night. I put the thick gray band right above my knees. I looked like a penguin trying to walk on ice. The thick woven fabric has absolutely zero stretch to it. I could only move my feet about three inches apart.
The medium band is slightly better. It actually stretches enough to let me finish a squat. But the heavy fabric pinches the back of my legs if I wear shorts instead of long leggings. The rubber threads woven into the inside of the band grip bare skin way too hard. I end up with bright red marks on my thighs after ten minutes of moving around.
I am going to stick to the cheap rubber loops for now. They roll up constantly and snap my legs when they twist. They are incredibly annoying to fix in the middle of a set. But at least they actually stretch enough to let me do the exercises. If you buy the fabric bands you basically have to wear thick sweatpants to use them without getting pinched.