How to solve the Atelier Blueprints Maze in Blue Prince - Atelier and Mount Holly Blueprints Rough Drafts guide

The Atelier is one of the game's secret areas, and reaching it requires the completion of several tasks first:

You must reclaim the Throne Room.
You must permanently unseal all Blue Doors.
A clue that you get from solving the Coat of Arms Puzzle tells you about Still Water.
You need to draft the Secret Passage as an outer room, and then you have to collect Still Water so you can interact with the bookshelf.

Doing the above grants you access to the Atelier and Mount Holly Blueprints Maze. However, there are a couple of caveats regarding this area:

You'll be walking around for quite a while. Ideally, you should have boosts to your number of steps the day prior, such as the +20 buff from the Sauna.
If the day ends, you must regain access to this area. Thankfully, don't need to recollect Still Water again. However, you must redraft the Secret Passage as an outer room. This can be a hassle due to the RNG with the Shrine.
If you don't think you have enough steps remaining for a single run, then we recommend forcing the game to close--i.e. Alt+F4 on PC. You'll be able to restart the day to better manage your moves--i.e. draft the Coat Check early so you have a lot of steps remaining.

Atelier and Mount Holly Blueprints clues: Documents and diagrams