Chemical composition is one of the key elements to trace the origin and the age of old papers. Elements such as cotton fibres shouldn’t be found in papers before 1790s when it was added to the paper compound.
But how can one be sure date a paper based item without the help of a microscope ? Well, there are other tricks to roughly estimate the age of a paper item. One of them is using the clues left by the paper making process.
At the very beginning, paper was handmade from bamboo pulp. It was a very specific industry and it has been thoroughly documented.
Paper is made from paper slurry poured or collected on sheet moulds created from wooden sticks in a mesh like pattern. The sheet moulds leave a diffuse but distinctive imprints on the paper sheets : the laid lines. When metal threads replace wood in the making of sheet moulds, those laid lines remained though slightly different in shape (thinner, less visible) and are a way to differentiate origins. The italian town of Fabriano seems to be the first European town where local paper milleries used specific symbols as watermarks starting in the XIIth century, with a first identified occurrence in 1282.
Around 1799, Louis-Nicolas Robert (1761-1828) created an industrial continuous paper making machine blueprint. The machine was constructed in England, under John Gamble’s supervision, and financed by the Fourdrinier brothers. A patent was granted in October 1801 and improved versions of Robert’s initial design were created up to 1806. From then on, the Fourdrinier machine usage in the paper making industry spread across Europe.
The machine is able to produce an almost endless roll of paper of whatever desired size. But due to its fabrication process, the produced paper doesn’t show laidlines. Industrially made papers from 1800 are of equal thicknesses on a specific production line and with no distinctives natural watermarks.
In 1826, John Marshall invents the “dandy roll”, a mesh covered embossing roll with a pattern that compress and reduce the paper slurry thickness in areas, creating a motif that can be exposed when the paper is backlit . “Watermarked” areas are thinner therefore can transmit more light.
In 1848, a variation of the dandy roll appears : the cylinder mould, allowing tonal depth and a much more clear and detailed watermark. It is the most common method used still today to watermark paper.
If you wish to go a little further into the identification and dating process of watermarks, you may find useful guidelines in this pamphlet by the French National Library.
Now, can you try and identify the dates and techniques used to create this piece of paper -watch out, there is a catch !-?
Complete answer available here!