One of the main reasons for patchy ceilings is uneven paint. If you roll on paint heavier in one area and lighter in another, it will look uneven. If you did patchwork before painting but didn't prime your patches, that can cause patchy ceilings as well. If your u003ca href=u0022https://diypaintingtips.com/best-paint-edger/u0022u003eedgesu003c/au003e dried while painting, this can also cause an uneven looking finish.