What is the difference between 'Coated', 'Matte' and 'Uncoated'?These designations refer to the surface texture of the paper itself. Coated paper, commonly used in high quality magazines, for example, has a shiny surface. This will affect the appearance of the colors and also tends to retard the absorption of ink into the paper.
Matte stock has a dull coating to it. Again, this will affect the appearance of the colors differently than a glossy coating and will also tend to reduce absorption. PANTONE guides and books on matte paper were discontinued in May 2010.
Uncoated stock has no coating, allowing for the highest degree of absorption of ink. Further, the absence of coating will produce a different look to the color.
In short, if you were to compare PANTONE 185 on the three different stocks, the colors would likely appear different, despite the ink and ink formulation being identical.