The coin and the T-account

Every bookkeeper draws the same shape when they want to think clearly about one account: a T. The account’s name sits on the top bar, debits go to the left of the stem, credits to the right. It’s the oldest diagram in accounting, and it’s the shape the ownpurse mark is built from.

Put one dot either side of the stem and the T becomes a face. The bar is a brow, the stem a nose, the dots two eyes. One eye is filled, one is open: the two sides of an entry. We noticed the face by accident, kept it on purpose, and drew it on a 96-unit grid so it stays crisp at 16 pixels.

Balance is the rule

The two eyes are the same size and sit on one axis. That’s double entry: every movement recorded twice, equal and opposite. So the identity has one hard rule: anything built from the mark is symmetric about its centre line. We tried lockups where “own” and “purse” sat either side of the stem, and they never balanced, because one word is longer. The mark and the wordmark now live apart.

The coin

The filled eye became a coin, and the coin became the o in the wordmark, cut to the exact size and baseline of the letter it replaces. It stands for money, for the purse, and for the merchants’ books of Renaissance Venice where double entry was first written down.

It’s also the only round thing in the system. Panels, tables and buttons are square, like a drawing board. When you see a circle in ownpurse, it means something: posted, open, held, short or over.

The blink

The open eye blinks every few seconds on this site, and it’s coming to the terminal UI’s header. It means the record is alive and watching. In the design, when the books are short the eye closes to a minus, and when they’re over it becomes a plus. If you prefer reduced motion, it stays still.

The full design system covers colour, type, the terminal theme and components. The logo files are on the brand page.