Designing the Kepler Pen

We’re major believers in the benefits of writing and drawing by hand. Whether we’re making lists of priorities, taking notes during meetings, or sketching new product ideas, the act of writing makes things easier to remember, and it’s just straight up more pleasant and fun than typing into our phones or computers. 

Since we launched Craighill in 2015 we’ve been curious about designing a pen, but it took years to find the right design and the right manufacturing approach. We’re extremely pleased with how the Kepler Pen turned out, and we wanted to shed some light on the process we went through to land on the design. 

We knew when we set out to design a pen that we wanted to explore mathematically driven and rational patterns for the pen body. We tested a variety of perforations, textures, and twists, ultimately landing on a waveform interpretation that touched on three of our top design priorities: a combination of beauty, functionality, and tactile satisfaction.

The Kepler Pen’s primary detail – the rhythmic wave pattern emanating from the tip – is based on the golden ratio. The spacing of the waves grows progressively farther apart in a logarithmic fashion as you move from the tip to the plunger. This was a very satisfying and exciting detail to zero in on when it emerged in the process of exploring and playing with the design. The undulating pattern helps add a sense of liquidity to the metal body, which is an unexpected material and visual contrast, and the tightly spaced ripples near the tip also create a comfortable, natural grip.

In devising a construction for the Kepler Pen, we focused on a distilled approach that centered on a precision clicker mechanism from Germany. The body is composed of a single component that is turned on a high-precision CNC lathe, and the entire assembly requires only a single spring. It’s a study in simplicity, and this production method helped to highlight and reinforce the continuity of the pattern running down the barrel.

We’ve always loved retractable pens – there’s still something very ingenious about the pen tip simply retracting when not in use, preventing errant marks. And you'll never need to worry about misplacing a pen cap. The actual act of retracting the tip is also extremely satisfying, as the resistance of the spring and the carefully dialed in proportions of the plunger create a smooth, heavy click. 

We chose to name the Kepler Pen for the mathematician and astronomer Johannes Kepler, who was particularly fascinated by the principles of the golden ratio and its magical properties of harmony and proportion.

While the Kepler Pen certainly travels nicely in a bag or even in a pocket, it’s perhaps most at home on your desk, paired with our Pen Rest and Desk Pad. Shop the Kepler Pen here.