Vermiculite insulation is a pebble-like, pour-in product that is light-brown, gray, or gold, often with shiny flakes or small accordion-like pieces.
Use R-19 or R-21 kraft-faced fiberglass insulation for 2x6 walls to ensure it fits snugly without being too loose or too tightly packed.
Unfaced insulation is ideal for new construction, remodels, and interior walls, floors, ceilings, basements, attics, and crawlspaces that do not require moisture control.