Outliner Brush Size 4 Series 840

Outliner Brush Size 4 Series 840 Mack Brush Series 840 Size 4, Hair Length Out – 1-3/4", Nickel Ferrules. The 840 Series Outliner is made with synthetic squirrel hair. This is a new synthetic that gives you the benefits of a natural haired brush. It is a soft hair that holds a lot of paint and gives you good snap. Andrew Mack Brush Co. Out-liner Brush Size 4 Series 840 Lettering and Pinstriping.