I know one even more effective game: it's called "job".
To play this game, you should craft an item "CV" and show it to NPC, called "HR". If item quality will be high enough, it will trigger dialogue. If you'll choose right dialogue options during it, you will unlock one-time access into special building, called "office". There you will talk with several another NPC. If you'll choose right options in all dialogues again, you'll unlock unlimited access to this building. At the next day, visit it again and you'll find here new unlocked quests, which you can complete for coins. Then exchange coins for Ink.
This way you can earn million Inks...
Too bad, this game requires too much time and boring grinding.
The most tiring game ever