The word solid in solid-surface does evoke the idea that this is a stable base (unlike bouncy laminates), but that is a peripheral meaning. Dupont’s true intent was to create a surface that was the same through-and-through. A homogenous product, Corian’s top is the same as its middle, and the middle is the same as its bottom.
Solid surface countertops are about 33% binding resins and 66% minerals. Those minerals are a bauxite derivative, Aluminium TriHydrate (ATH). ATH is a kind of fine, white powder that helps Corian maintain its smooth consistency. Contrast this with quartz countertops, which are about 10% resins and the rest minerals.
The idea behind Dupont’s invention was to have a surface that looked like natural stone, but unlike stone, was non-porous. Slice granite and you will see a wild make-up of particles forming the slab. Beautiful, indeed, but offering up multiple avenues for cracking and breaking. Polyester-based solid surface counters are cheaper but are considered inferior to newer acrylic-based counters.
Polyesters tend to impart more vibrant colors than acrylics. Acrylics are great if you need to do any fancy fabrication work, like thermoforming.