What is bronzing and Gloss Differential?
General Queries -
Bronzing is where, when paper is viewed from an angle, part of the image seems to disappear or take on a uniform tone – usually bronze. It occurs because some of the ink that has been laid onto the paper hasn’t properly absorbed into the coating and instead sits on the surface of the paper. With new pigment inks this problem has been almost completely eliminated.
Gloss differential can occur when using pigment inks with glossy or semi-gloss papers. It is a visible difference in the glossy surface of a print which is caused by a contrast of different amounts of ink being laid being onto the paper. For example, in highlighted areas or areas of white, very little ink will be laid onto the paper. If this is surrounded by an area of more heavily laid ink then this area will appear as more reflective and can be seen to stand out when the paper is held at certain angles.
To avoid gloss differential, you can either use a printer with a chroma optimizer / gloss optimizer ink, which adds a glossy layer over the print to minimise the difference between the printed and unprinted areas. Or, if you are using a printer that doesn’t have one of these inks, we would suggest to use a protective spray, such as Hahnemuhle Protective Spray, over the print which again will minimise the effect of gloss differential.