Portrait Primary: 0.205- 0.211 mm Secondary: 0.253- 0.257 mm, Tertiary: 0.160- 0.173 mm All three supports are machine-made, craft quality paper. The primary support is yellow/cream in color and smooth. The media is painted on the wire side. The secondary support is orange and smooth, slightly thicker than the primary. The black tertiary support is internally dyed, soft and is the thinnest of all three supports.