christina mitrentse, ”Skoob Tower I’ after John Latham’, Penguin vintage 50’s editions by greenwich bookdealer, printed covers, light installation, 2011. Courtesy: christina mitrentse & Trinity ∴. A geological ‘core sample’ or stratification of the history of Penguin books ! Stratification Stratification is the building up of layers. Stratified is an adjective referring to the arranging of layers, and is also the past form of the verb stratify, to separate or become separated into layers. They may refer to:In mathematics, statistics and applied science. For the use of stratification in mathematics and statistics, see Stratification (mathematics). Stratified sampling, in statistics Stratified fuel charge, or ultra lean burn, the use of lean mixtures in an internal combustion engine with unequalized pressure in the cylinder Fuel charge stratification, an internal combustion process using gasol