The blade spine typically refers to the thickest and fullest portion of the blade. On a single-edge flat-ground knife, blade spine always refers to the outermost back of the blade. On a classic dagger, the spine refers to the fullest-thickness part of the blade running straight down the middle. On knives with false edges, the term "spine" is used inconsistently. Technically, the spine would be the fullest and thickest part of the blade where the main bevel meets the false edge bevel. However, blade spine is often used to describe the back of the blade instead, right over the false edge.