Bip39 Mnemonic Words. From this stage ahead the seed could be penned on paper or spoken in excess of phone and this opened up new, Bodily means of backing up the seed (several paper copies in various places, long lasting copies on metal plates with more protection from hearth/flood etcetera.). https://marcooetix.wikitelevisions.com/6904108/the_anatomy_of_the_bip39_phrase_entropy_words_and_phrases_and_protection