Printing in PLA, I’ve noticed that shortly after a retraction (a few seconds later), I hear a little air bubble pop/snap sound. It leaves a tiny litle pit on the print. The sound and pit are very similar to the problem you might face using damp filament. this though is totally dry, and it only happens shortly after retractions. Has anyone else noticed retractions introducing air into the nozzle? If so, any tips?
This is a close-up detail. These are .25mm layers.