Carbro Surface View
Surface Sheen
A key identifying feature of carbro is differential gloss caused by the difference in surface sheen between the shadows and highlights due to a slight image relief; the gelatin is thicker in the shadows. Glazing was an optional finishing technique to give the print higher surface gloss. The print could be dipped in a 10% solution of gelatin while still wet or rubbed with wax when dry. This treatment may reduce differential gloss.
A key identifying feature of carbro is differential gloss caused by the difference in surface sheen between the shadows and highlights due to a slight image relief; the gelatin is thicker in the shadows. Glazing was an optional finishing technique to give the print higher surface gloss. The print could be dipped in a 10% solution of gelatin while still wet or rubbed with wax when dry. This treatment may reduce differential gloss.
What to look for: Differential gloss, a difference in surface sheen between the shadows and highlights. Prints with higher surface gloss overall may have been glazed with gelatin or wax.
Differential gloss is the difference in surface sheen between the shadows and highlights because the gelatin is thicker in the shadows and therefore has a higher gloss.
Surface Texture
The paper support of some carbro prints consists of heavy weight paper coated with gelatin. The lack of a baryta layer allows the texture of the paper fibers to come through giving the highlights a slight texture. However, some carbro prints are on baryta and the paper fibers are obscured resulting in a smoother surface. Many carbro prints have matting agents present giving the surface a slight texture likely intended to diminish differential gloss. The thickness of the pigmented gelatin in shadows will create a smoother surface. This results in a slight image relief, which is seen as differential gloss using specular light.
The paper support of some carbro prints consists of heavy weight paper coated with gelatin. The lack of a baryta layer allows the texture of the paper fibers to come through giving the highlights a slight texture. However, some carbro prints are on baryta and the paper fibers are obscured resulting in a smoother surface. Many carbro prints have matting agents present giving the surface a slight texture likely intended to diminish differential gloss. The thickness of the pigmented gelatin in shadows will create a smoother surface. This results in a slight image relief, which is seen as differential gloss using specular light.
What to look for: Slight image relief, usually noticeable as differential gloss. Slight texture due to the presence of matting agents and sometimes paper fibers.
The presence of matting agents and no baryta give prints a slightly textured surface under raking light.