I printed PiezoPro with Canson Platine curves: it knew to apply gloss overprint?

I loaded a sheet of Canson Platine and selected the appropriate curves for that paper.

I forgot to reconfigure my Epson 3880 from Matte to Gloss, but I made a print.

The print came out with a gloss overprint, perfecto. It knew ? What a pleasant surprise. Does this mean it saves ink because there’s no need to “change” inks ?

The LLK channel printed because of the curve but most likely you still have a TINY bit of funkiness in the shadows if you are printing matte black under there. These gloss prints use a very small amount of Shade 1 ink though so it has the possibility to look ok.

best,
Walker

Thank you Walker.
Does that mean we should explicitly switch to Glossy ink before printing with glossy paper and curves ?

yes you should switch to glossy (black) ink whenever printing on glossy paper.