Felt is a non-woven fabric made up of layers of fibre. Some felt is made from wool, but a lot of craft felt is made from synthetic fabrics.
Felt is a great crafting material. It does not fray and is easy to cut and sew or glue, making it ideal for kids' crafts. Most of the craft felt you'll find on sale in craft or toy stores is made from synthetic fibres, such as acrylic.
Some scientists have raised concerns about the impact of plastics on the environment. If you're trying to reduce the environmental impact of your materials, the prevalence of synthetics can be a problem, especially if you want to get your kids involved in a greener lifestyle. One solution is to use felt that is made from recycled plastics.
Recycled Synthetic Felt
Some synthetic felt is made from recycled plastic. The waste plastic is melted down and spun into fibres, which are then felted. Recycled synthetics have a lower environmental impact than non-recycled synthetics. Bear in mind though that once made into fabrics like felt, the materials probably can't be recycled again.