I typically carry these while climbing to build anchors and to cut for rappel slings on the way down. The more I know about the adverse effects of using static materials, for belay anchors, the better I feel about using dynamic a cordelette, if using the rope isn't possible.
DMM, the excellent climbing company in Wales, has some videos showing about increase of impact forces on anchors with various types of dyneema and nylon runners on their website.
Pre-cut lengths of 100% nylon Edelweiss cord -7mm in diameter offer great solutions cordelettes, and anchor systems. Unlike regular 7mm cord this has a dynamic core,just like a climbing rope to reduce impact forces on the anchor.. Assorted colors.