Bip39 Word List Trezor. From this place forward the seed may be composed on paper or spoken about phone and this opened up new, physical means of backing up the seed (multiple paper copies in several spots, tough copies on metallic plates with more protection from fire/flood etc.). This tool https://codyyncqe.pennywiki.com/4316193/the_anatomy_of_a_bip39_phrase_entropy_words_and_protection