protected override void OnRenderSeparator(ToolStripSeparatorRenderEventArgs e) { if (!e.Vertical) { using (Pen pen = new Pen(this._borderColor)) { Rectangle rect = e.Item.ContentRectangle; e.Graphics.DrawLine(pen, rect.X + 25, rect.Y, rect.Width, rect.Height); } } else { base.OnRenderSeparator(e); } }