Featured Porcelain coasters from Italy, what do I call this edge issue?

I've already ID'd these, just want to get some descriptive words for some issues on a few edges. Obviously I could say "flea bites" but I don't think that is correct. I suspect instead that the rough spots possibly came out of the manufacturing process. If I'm correct, there a descriptive word for this?


Several photos below of what I'm talking about. There is another partial set online and they describe "edge wear" and it looks a bit like this. So apparently not just my set. Areas are rough to the touch, and at first I thought a chip or fleabite, but when you look at a close-up almost looks like maybe where the coaster was held by the edge during the manufacturing process possibly? Looks like the glaze is pushed aside a bit:





I suppose could be a combination of things, but this is the only wear on these, all exactly in the same spot --some have none, but those that do are in exactly the same location.


Anyone have thoughts or words to describe this? Especially the spots where the glaze seems to be pushed over. Thanks!

 

I can only think of 'fritting', but that doesn't describe that pushed glaze effect.

 

I suddenly thought of 'burrs', and that is what these people call those clay pushed 'things':
https://thepotterywheel.com/sanding-pottery/

 

That looks like kiln frit - something went bang in the kiln and bits of flying ceramic caught on the glaze while still sticky. Very common in Georgian and Victorian times, less so in the 20th century. Looks like the QA wasn't bothered here, I quite like quirks like this, it's not damage, just something that happens during manufacture.

 

Thank you AJ and Ce BCA.

 

Underglaze manufacturing nibble.

 

Marks like these occur during the commercial ceramic production process when multiple glazed plates are placed in the kiln and separated by stilts, wedges, wires or some sort of device to prevent the glaze from sticking the plates together. (Stilt marks are often found on the bottoms of plates, pots, cups, etc.)

 

Totally off topic, but does anyone know what the caption says below the illustration? Just curious.