Paper Making

Iron oxide pigments are inorganic pigments used as fillers in certain specialty papers, but their application is not widespread. These pigments belong to the group of iron-based colorants, and typically only four types are used: iron oxide red、yellow、black and brown.

The common characteristics of iron oxide pigment are that they are insoluble in water and have no affinity for pulp fibers.  They need to be fixed onto the fibers with the help of alum to achieve coloring and act as a filler. Iron oxide pigments have strong lightfastness and good covering power.

In high-grade decorative base papers (such as pine wood pulp paper), iron oxide pigments not only act as fillers but can also partially replace expensive titanium dioxide, while simultaneously providing coloring functions and replacing costly and highly polluted organic dyes.