Most budget mattresses have little reinforcement along the edge, so when you sit there to tie your shoes or read a bedtime story, it collapses under your weight.
While even our least expensive models are built sturdier than most others, featuring border rods, corner cups, and butterfly clips, but those still can’t perform as well as a foam-encased edge.
With foam encasement, there’s a perimeter of foam blocks around the coils to create a sturdy edge that responds along with the coils, so you can sleep all the way to the edge without feeling like you’re about to fall off, and you can sit comfortably without having it collapse.
Above we see a foam encased mattress being assembled at the factory. The coil units fits snugly inside, and the foam blocks connect all four sides to create a sturdy perimeter support. It's the best edge system you can get!