Laser welding is increasingly adopted due to its cleanliness and design flexibility. However, its broader application is constrained for instance by material properties, such as transmission limiting weld strength especially in high-performance polymers. This session presents breakthroughs in laser transmission welding, for instance laser-welding of polyphthalamides (PPA’s) and will present a newly developed absorbing-to-absorbing laser welding technique. These innovations enable more robust welding, design-flexibility in demanding environments.