Yeah, every six months actually. I should do the same to mine. Though I heard not all mattresses can be flipped - in which case you just turn them around.
Hmm not sure if it was 20 but then you dont need to keep flipping mattresses ;p more than enough to just switch every so often~ I do wonder what happens if she accidentally rolled a bit while sleeping ;p
If we're talking spring mattresses, then I'd say about 10 feet, at least? Though in one version I read, the Queen called for 'all the spare mattresses in the castle' and not just 20 but meh, who knows? xD
Hello, could you please reupload the mexashare or Katfile links for https://www.anime-sharing.com/threads/161222-softhouse-seal-grandee-ぜったい遵守☆にゅ~こづくりわーるど.566758/#post-2589631 . Would really appreciate it.