Standard coated art cards (250gsm Art Card, 310gsm Art Card, 360gsm Art Card) have a surface layer that reflects light. This makes colours appear vibrant and sharp. However, it also gives the card a slick, plastic-like sheen.
Natural premium stocks like 360gsm Natural White and 250gsm Champagne Frost are uncoated. They are made from genuine paper pulp. You can see and feel the fibre texture. When ink hits this surface, it is absorbed rather than sitting on top. The result is a soft, matte appearance. It does not glare under office lighting or sunlight.