The first examples of flexible consumer electronic devices are now a reality, and a large opportunity lies in developing them further: devices in a flexible form factor that can operate without deterioration in performance, allowing them to be more robust, lightweight and versatile in their use and form factor is the end game . In order for products such as flexible displays and photovoltaics to be commercially successful, they must be robust enough to survive for the necessary time and conditions required of the device. This condition has been a limitation of many flexible, organic or printable electronics. This highlights the fact that beyond flexibility, printability and functionality, one of the most important requirements is robust encapsulation; this is a major challenge as many of the materials used in printed or organic electronic displays are chemically sensitive, and will react with many environmental components such as oxygen and moisture. Plastic substrates and transparent flexible encapsulation barriers can be used, but these offer little protection to oxygen and water, resulting in the devices rapidly degrading. In order to achieve device lifetimes of tens of thousands of hours, water vapor transmission rates (WVTR) must be 10-6 g/m2/day, and oxygen transmission rates (OTR) must be < 10-3 cm3/m2/day. For Organic Photovoltaics, the required WVTR is not as stringent as OLEDs require but is still very high at a level of 10-5 g/m2/day. These transmission rates are several orders of magnitude smaller than what is possible using any conventional plastic substrate, and they can also be several orders of magnitude smaller than what can be measured using common equipment designed for this purpose.