I belong to a church group that help our homeless here in St Augustine , (4 S -sweaters-socks ,soup and salvation) the plarn(yarn made out of plastic grocery bags) is very durable.When we give a homeless person a mat, they are very glad to get one.It takes between 500-600 bags to make one mat.We only have one person that crochets them for us, but a lot of the congregations donate their bags.