Inkjet printing is a nascent technology that developed during the last decades from only printing text and graphics into an important scientific research tool for R&D, where printers are used as a highly reproducible non-contact patterning tool. In contrast to lithography, inkjet printing is an additive technique that requires only small amounts of functional materials and, therefore, has a high materials efficiency. In particular, inkjet printing of metal nanoparticle dispersion has been used more and more during the last few years, in order to produce conductive features for plastic electronic applications.Here, we present our recent results in the sintering of inkjet printed metal nanoparticles on polymer foils. In order to sinter the particles at speeds that are compatible with roll-to-roll speeds, we have used a combination of sintering methods. Conductivity values between 40 and 60% were obtained in a few seconds to minutes by using either photonic or plasma pre-sintering combined with microwave flash sintering.