Hi Chris, You need to enable this feature; it is Off by default. New features summary | January 2018 and October 2017 releases of Photoshop CC New in the October 2017 release Default state: Off Photoshop now lets you paint symmetrically while using the Brush, Pencil, and Eraser tools. While using these tools, click the butterfly icon ( ) in the Options bar. Choose from the several available types of symmetry. Paint strokes are reflected live across the line of symmetry, allowing for easier sketching of faces, cars, animals, and more. To enable this feature, select Preferences > Technology Previews > Enable Paint Symmetry. cheers, steve
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