Flake is a popular traditional format of pipe tobacco. Cut from large pressed cubes of tobacco, flakes retain a much deeper flavour than most shag cuts. To prepare flake for use, most people rub it down to a more favourable consistency. Others choose to smoke it as is, just rolled and placed in the chamber.
Plug is a form of pipe tobacco utilising full tobacco leaves that are pressed and then aged. The result is a highly condensed brick of tobacco that requires slicing before its smoked.