Here's why:
* Erasers are a common noun: They refer to a general category of objects.
* Brand names are proper nouns: For example, "Pilot" is a proper noun because it refers to a specific brand of eraser.
* Types of erasers can be capitalized: For example, "Pink Pearl" might be capitalized as a brand name or to refer to a specific type of eraser.
Examples of specific eraser names:
* The Pink Pearl (a specific type of eraser)
* The Pentel Clic Eraser (a brand and model of eraser)
* The "Magic" Eraser (a type of eraser with a specific function)
It's important to remember that proper nouns are always capitalized.