Iris Fall

This achievement is awarded for solving the typewriter puzzle in Chapter 6 in one attempt. To gain access to this puzzle, you must first head downstairs to the podium in the center of the room at the start of the chapter and interact with it. A triangular puzzle will appear. To solve it, follow this pattern:

One, Five, Five, One, Four, Five, Five, Five, Four, Four, One, One, One
Solving this will spawn the huge projection puzzle and some butterflies. Ignore the protection puzzle and head over to the butterflies to your left. The symbol on each butterfly's wings correspond to the number book they're on. Use the photo below for reference.

Interact with the typewriter and enter in the symbols in order of book 1-5.
For the photo above it would be: Big dot/little dot, diamond, bulls-eye, swirl, bulls-eye. This may be the same order for everyone, but I'm not certain. If you solved this puzzle in one attempt, you will unlock the achievement.

The butterflies have symbols on their wings and they are on books with 1 to 5 dots on them. There are keys that represent the 4 symbols. Press the key for the symbols in the order of the dots on the book. For me it was

First Key - Curly Symbol
Second Key - Big dot, Little dot
Third Key - Bullseye
Fourth Key - Diamond

1 big dot little dot, 2nd Key
2 diamond 4th key
3 bullseye 3rd Key
4 curly symbol 1st Key
5 bullseye 3rd key

MISSABLE.
Iris.Fall - 100% Achievement Walkthrough + Commentary
Timestamp
Chapter 6
25:15 Ink Saver