Machine weft hair extensions can be suitable for many types of hair, but it depends on the individual's hair texture and density, as well as the type and quality of the extensions being used. At Perfect Locks, we only use the finest virgin hair for our Natural Black #1b, and Remy hair for our colored machine wefts. Some types of hair may not be able to support the weight of extensions, while others may be too fine to blend well with the extensions. Additionally, if someone's hair is already damaged, or if they are prone to hair breakage, extensions may not be suitable. It's best to consult with a professional stylist to determine if machine weft hair extensions are suitable for an individual's hair type and to ensure proper application and maintenance of the extensions.