Felt: Wool fibers insulate year round, promoting breathability with a comfy and lightweight essence.

However, some find felt to be too stiff for their liking, and the price point can also be high.

Synthetic/natural blends: Cotton, polyester, and spandex are all practical and durable options that are budget friendly and low maintenance. 

Depending on the ratio of materials, breathability and insulation can be a concern.

Price

Slippers can start at $5 and can run upwards of $80.  For $5 to $15, slippers include minimal insulation and protection from floors, while the $30 to $80 price point offers more luxurious and orthopedic aspects. 

For $80 and up, you can expect premium materials and durability, often coming from designer brands.