Oil filter cartridges constructed in the past are typical mainly for solid casings. Metal bottoms and inner core of perforated plate assure good compressive strength and temperature changes resistance. Filter media are made of special filtering papers based on cellulose fibres to filter the oil efficiently and assure maintaining its good properties during exploitation. Quite often, the media are protected from outside with perforated paper or even metal net. Those casings, apart from protecting the pleats from mechanical damage, also make the filter medium rigid and prevent from deformations and pleats sticking. High utilisation cost and application of environment friendly materials caused replacing these models by "ECO" cartridges which do not contain metal parts.