Pocketed Coils
Support coils individually wrapped in fabric pockets, allowing each coil to compress independently. Standard construction for modern hybrid mattresses.
Pocketed coils (also called individually wrapped coils, encased coils, or Marshall coils) are support springs each enclosed in a fabric pocket and arranged in a grid. Unlike traditional interconnected innerspring construction, pocketed coils compress independently — each one responds only to direct local pressure.
This independence is the source of pocketed coils' two main performance advantages: motion isolation (a partner moving on one side doesn't transfer force through the spring grid) and contouring (each coil shapes to body weight at that exact location).
Modern hybrid mattresses use pocketed coils as the support core, topped with foam, latex, or polymer comfort layers. The combination delivers the airflow and bounce of a traditional innerspring with the pressure relief and motion isolation of a foam mattress.
Coil count, gauge, height, and zone configuration all affect feel. High-end hybrids zone the coils — using firmer coils under the lumbar and softer coils under the shoulders — to deliver targeted support without sacrificing pressure relief.
The fabric pocket is doing more work than most shoppers realize. Because each coil is wrapped and free to move independently, force does not travel laterally through the spring system the way it does in a connected innerspring unit. That is the entire mechanism behind the 'my partner gets up and I do not feel it' claim on hybrid marketing.
The trade-off is durability at the seams. Pocket fabric can tear or the glue joining pockets can fail, allowing coils to shift and cluster — the cause of that lumpy, uneven feel some hybrid owners report in year four or five. Better beds use welded or sewn pockets rather than adhesive alone, which is worth asking about on any mattress you expect to keep a decade.
What This Means for Shoppers
If you share a bed with a partner, pocketed coils are non-negotiable. The motion isolation difference vs traditional Bonnell or continuous-coil innersprings is dramatic — the difference between waking up every time your partner shifts vs sleeping through the night.