Um? So what is that ? - Some of you may be asking yourself that now.
My 3D printer elaborately produces stamps for your (and of course mine) ceramics. He does this by melting a "string" and using it to build up a little masterpiece, layer by layer.

3D printed stamps are not comparable to cast goods, you can see that the stamps are made of “strings”.
The close-up shows it very clearly, the appearance varies depending on the filament (these are the cords in question, the "printer's ink" so to speak).