The penetration of polymers by solvents has implications for diverse fields, such as the packaging of liquids and drug delivery. In experimental studies of this uptake processes, one aims at the spatial distribution of the solvent as a function of time. In a recent joint study with the group of Stefan Egelhaaf, we demonstrate that femtosecond stimulated Raman microscopy (FSRM) - developed in house - is a very suitable technique for this purpose. Read more in 10.1021/acs.macromol.9b00205