Ah! Yep, didn’t see it at all! Just replayed it and I realized that you have to click right on the hanger but there is a larger area that triggers the translucent version so I thought putting it away initially wasn’t working. Given the absurd pile up of books, in this case being more generous with clicking is probably the way to go but the game is indeed much more enjoyable now that I know how to play all of it an not cheat :)