One of the surprises in this study was the presence of aluminum and silicon in the pcc. Mapping of these elements, shows that they are distributed in a similar fashion to the pcc (Figure 10). The most likely form for these elements is as clay particles which introduced by recycled pulp or as impurities in the pcc. The presence of the clay in these papers was unexpected and may have undesirable consequences with respect to print quality.

Figure 10 Maps of one area (Sample C9) for Al a), Si b) and Ca c).