Everything Flattening and Removing Extra Strokes The Flatten and Remove Extra Strokes command allows you to flatten the selected artwork together and instantly remove invisible lines that are adjacent to it. NOTE This will only remove invisible lines that are adjacent to visible artwork. Invisible lines that are not connected to any visible shape or line will not be removed. How to flatten artwork and remove extra strokes In the Tools toolbar, select the Select tool. In the Drawing view, use the Select tool to select the artwork that you want to flatten and clean up. In the top menu, select Selected > Flatten and Remove Extra Strokes.