The first form of slate writing was produced on two 5”x7” clean school size slates, placed side by each. A “school slate” was first used during the days of the one room schoolhouse, paper was expensive and in short supply and the children would each hold a small slate on which to write, after which the lesson could easily be erased, thus no paper would be wasted. A small piece of slate pencil was placed on one side of the slates; the slates were fastened together on top of each other. As the years passed by and the small school sized slates were more difficult to find a similar sized box was made that could also be securely fastened together; except a 5”x7” index card was placed in the enclosed area with a lead pencil tip broken off and placed within the enclosed box.
During the second half of the 19th century and early 20th century, pencils cut from solid pieces of soap stone were used by school children for use in the class room to write on 5”x7” tablets cut from the harder grades of slate. Slate pencils were available with the slate core unwrapped, wrapped in paper or encased in wood. Slate pencils were advertised as late as 1914, wood cased slate pencils were still sold as late as the early 1930’s but were difficult to obtain. The chalk used today, (black board chalk), which is used on the large schoolroom black boards is made from calcium sulfate and is primarily of plant origin.