100% interlocked hoghair blue handle Neef 1150. This bristle leaves brush marks in the paint film where required and only the best quality Chunking bristles are selected. An extra length of hair is inserted into the ferrule, formed into a mould and oven heated for a short time this gives the bristles greater spring. All of this quality control enables the interlocked bristle to retain its shape and resilience over many years. Chungking bristle hoghair is specially prepared to give the best quality results over many years. We recommend these brushes to oil painters. If you look after them they will last a very long time and improve with use.