C stands for Coated paper, U stands for Uncoated paper. ... PMS 250 for example will look very different on a coated stock vs and uncoated stock due to the papers surface. At the end of the day, for printing your artwork, there is no difference between C and U pantone colors.
How do I choose a Pantone Color? Choose the right swatch from your screen. First, pick the color that you want on your screen. Then find a Pantone swatch in your book to match — coated or uncoated depending, on your print surface.
When customizing a leather cover notebook, the material can be produced as per the color code from Pantone. Just choose the color code you prefer from the book, a perfect notebook can be presented after days of production.