Abstract: A paint brush accessory mountable on a paint brush includes a planar shield having a first edge and an opposed second end. A guide is carried on the shield adjacent the first edge for sliding engagement with a surface or edge to enable the shield to be guided in a straight line at an angle along the surface or edge. The guide is formed with an exterior surface disposed at an angle with respect to the plane of the shield to hold the shield at a constant angle from an adjoining wall when the first edge of the shield in engaged with a surface or edge. A holder is pivotally coupled to the second end of the shield to enable pivotal movement of the first end of the shield between a first position adjacent the bristles of a paint brush and a second position spaced from the bristles. The holder is releasibly mountable on the paint brush handle.