Tamil Sandpaper letters are a foundational Montessori language material consisting of tactile letters cut from fine sandpaper and mounted on individual wooden boards. They are designed to engage a child's visual, auditory, and kinesthetic senses to build a strong connection between the shape of a letter and its phonetic sound. 
 
The letters are traditionally color-coded to help children distinguish between different types of sounds: 
Consonants: Mounted on pink or red wooden boards.
Vowels: Mounted on blue wooden boards.