In short, the knight in shining armour image is a product of storytelling rather than reality. The shiny appearance comes from the misconception that armour was always made of polished steel. As it turns out, armour was made from a variety of materials including leather, chain mail, and plate armour.
There is no greater glory than the honor of knighthood.
— Sir Thomas Malory
And, well, the primary purpose of armour was to protect, not to look pretty and sparkly.
Polished armour would quickly become scratched and dull in battle. Plus, keeping armour shiny would have been extremely labour-intensive and expensive.
King Henry VIII's armour, currently in New York
Our image of the knight in shining armour has been heavily influenced by Hollywood and books.
