Is this the original French Canson watercolor paper? Why was there the name Barbizon? What did it mean by neutral and no acid?

I can't confirm if the product you mentioned is the French Canson Watercolor Paper because I can't get the relevant brand or model information. At the same time, the name Barbizon did not mean that the product was Canson watercolor paper. It might just be one of the product series names of the brand. Neutral acid free was a chemical term that referred to a substance that did not produce an acidic or basic reaction. In the paper manufacturing process, neutral, non-acid paper is usually made of non-acidic or non-basic raw materials to ensure that its pH-value is around 7 and will not negatively affect the skin.