Micro glass beads are currently the most popular and common weighted blanket filling.
Glass beads are highly durable, hypoallergenic, and odorless, and the most popular weighted filling of choice for most people.
You may want to keep in mind that there have been some reports of cheaper glass beads containing lead. So always look out for hypoallergenic, non-toxic glass beads (a quality weighted blanket should contain these).
You’ll also find some commercially made weighted blankets, supplemented with a cotton or polyester fill, to provide extra padding and protect the beads.
Considered high quality due to their smooth edges and consistent shape, microbeads are usually considered the most ‘luxurious’ weighted filling, as well as the smoothest and ‘quietest’ (i.e. glass beads don’t rustle about).
A bit like grains of sand or sugar, they’re much smaller than the ‘pebble’ like plastic poly pellets, which were traditionally used as a weighted blanket filler when they first emerged as a sensory tool used by occupational therapists.
Although generally a little more expensive than plastic poly pellet fillings, glass beads are heavier, which means you need less of them.
Due to their tiny size and weight, glass beads sit very densely inside a weighted blanket, which allows the blanket to lie more smoothly on the body than blankets filled with a bulkier filling. This ‘density’ also makes the blanket thinner and flatter and, for many people, less ‘clumpy’. This often makes glass beads the best option for highly sensitive people.