I think what you mean to say is when did blue "ruled" notebook paper become widespread. Lines on a writing medium have been around a long time with monks from the medieval period marking lines (they would use a wooden stylus to make a creased line) upon with scripture could be uniformly written on vellum. In the late 18th century in Europe with composed music becoming more popular, having methods of drawing out sheet music was in demand and thus notebooks and paper with ruling for music notation became a product. In the book "Papermaking, The History and Technique of an Ancient Craft" by Dard Hunter mentions that an English patent for a ruling machine was granted in 1770 to a John Tetlow. I tried finding other information on specifically when blue ruled paper became more common but with various answers all over the place. I can safely say that they were common around 1860 and might have even been around in the early 19th century. This shouldn't be surprising though because standardized blue ruled paper came about in the midst of the industrial revolution.