Type Alias Matrix 

pub type Matrix = Vec<Vec<u8>>;

Type alias for 1-bit bitmap data used by printers.

Each inner Vec<u8> represents a single row of pixels, with 8 pixels packed into each byte. The outer Vec represents multiple rows.

For normal printers: each row should be 90 bytes (720 pixels / 8) For wide printers: each row should be 162 bytes (1296 pixels / 8)

Aliased Type

pub struct Matrix { /* private fields */ }