I was smoothing a few nibs today, some from modern fountain pens and some from vintage. I did notice that the final result favored the modern fountain pens and not the vintage ones, despite the fact that the same polishing method was used. Specifically I got much more buttery effect out of a plain parker IM fountain pen with a steel nib, compared to a parker 51 with a gold nib. This got me thinking whether this had to do with the tipping of the nibs and the slit cut. I imagine that modern pens take advantage of new technology which has provided better methods to apply tipping at the nib and to cut open slits for the ink to flow. Is this something that may explain the difference between the smoothness of the nibs? Meaning the parker 51 having a more "rough" (with air pockets) tipping or inner tines, due to inferior manufacturing process, compared to the one we use today.