I just got gifted with a half-dozen Classico spaghetti sauce jars. I
know that zxcv Bob uses such jars with good results but does anyone
else? They're marked Atlas Mason, are good sturdy canning type jars, a
regular jar ring fits them perfectly with no leakage (yes I wasted a
lid) but I'm unsure, as yet, of the amount they contain. Looks to be a
little larger than a quart but I will measure the amount perzactly to be
sure.

Speak, O Guru's of the pressure canner.