480 Sheets Total
Twelve pads at 40 sheets apiece is a supply that outlasts a semester. One pad lives at the desk, one in a backpack, one in the kitchen drawer, and the rest stay sealed until they are needed. Teachers hand them out by the pad to a table group. Buying in this quantity also means notes stop being saved for important things, which is the failure mode of a single pad kept in a drawer.
Three Inch Squares
Three inches square is the working size for a reminder, a question in a margin or a step in a plan taped to a wall. Written on and stuck to a textbook page, the note stays inside the book when it closes. On a monitor bezel, two or three fit across without overlapping. On a fridge it holds a grocery list that everyone in the house can add to.
Color As Code
The assorted colors are more useful than decorative once a system attaches to them. One shade for deadlines, another for questions to ask in office hours, a third for pages to revisit before an exam, and a chapter becomes navigable at a glance. The same logic runs a classroom wall or a project board at work, where a color tells a passing colleague what a note is about before they read it.
Desk Drawer Staple
Most of these sheets will never do anything memorable. They will carry a phone number, a reminder to move the laundry, a note left on a partner's keyboard. That is the job. Keeping a stack in the drawer at home, another in a classroom cupboard and a pad in a bag means the thought gets written down at the moment it arrives rather than trusted to memory until evening.
