Board Thread:Theories and Speculation/@comment-34656247-20191119070420/@comment-34656247-20191122214310

In every instance where Itachi uses amaterasu on chakra based substances it burns fast.
 * The toad stomach
 * Orochimaru's snake
 * The crow with shisui's eye
 * vs Sasuke's fire style

When it appeared on Obito, with all that time Obito spent falling back, screaming etc his clothing would've at least been burnt....but there was not a scratch. You know what revives the user in an uninjured state? izanagi does.