Question

Which material is often added to engobe for coloring?

• A. Silica
• B. Ball Clay
• C. Metal Oxide
• D. Alumina

Hint:

Metal oxides such as cobalt, iron, and copper are commonly used to color engobe and glazes.

Answer 1

The Correct Option is C

Step 1: Understanding Engobe and Coloring.
Engobe is a liquid clay mixture applied to ceramics before firing. Metal oxides are often used in engobe to provide various colors, such as red, blue, green, or brown.
Step 2: Analysis of options.
- (1) Silica: Incorrect, silica is typically used to form the glassy phase in glaze, not for coloring.
- (2) Ball Clay: Incorrect, ball clay is used for its plasticity, not for coloring.
- (3) Metal Oxide: Correct, metal oxides like iron oxide, copper oxide, or cobalt oxide are commonly added to engobe for color.
- (4) Alumina: Incorrect, alumina is used for durability and hardness, not for coloring.
Step 3: Conclusion.
Thus, the correct answer is (3) Metal Oxide.