If they drop new collections in large numbers, this is a fast fashion business model.
A slow fashion brand focuses on its niche, not on trying to please everyone. Look for core styles on offer year after year.
Sustainable Fashion brands always create clothes that can be worn, washed and used over years. They create products that can last and can be passed on to the next generations.
Make sure the brands are transparent about recycling, refurbishing and mending programs