iron

Ingredients

terracotta, iron

Preparation Steps

Original Recipe Text

The color is generated in situ by using a carbon dioxide flat-bed laser (40 watt) as a heat source on unglazed fired terracotta (p. 122, 123). When the laser is applied to the iron-rich terracotta, it causes permanent marks in the form of black glazed lines (p. 122). The process changes the molecular structure of the surface (p. 124).

Evidence

"Konstantakou believes that terracotta is the best type of clay to use with laser as it contains iron which discloses various tones of blacks, reds and purples, that is impossible to obtain with white clays (Konstantakou, 2021)."

Remarks

The author identifies this as a 'happy accident' or 'surprise' discovery (p. 121, 123). Unlike applied pigments, these marks are permanent and will not fade (p. 124). Tones of blacks, reds, and purples are achievable due to the iron content in the terracotta, which is not possible with white clays (p. 124).