Parafilm is a plastic paraffin film with a paper backing , primarily used in laboratories. It is commonly used for sealing or protecting vessels (such as flasks or cuvettes). It is ductile, malleable, waterproof, odorless, thermoplastic, translucent and cohesive.
It is also used to further seal a lidded container against moisture and air contamination for long term storage. However it is also claimed that Parafilm breaks down over time on exposure to air and light and so does not serve as a long-term sealant.
Volatile organic solvents will dissolve Parafilm.
Parafilm is used by some modelers as a masking material during airbrushing, due to its lack of adhesion, which can destroy a finish.
A new application of Parafilm is to make paper-based microfluidic device. Paper-based microfluidic devices are considered a suitable way to fabricate low-cost point-of-care diagnostics for developing countries and areas where expensive medical instrumentation is not accessible.