In 2006, Design Within Reach commissioned Spiekermann to design house numbers; a three-dimensional typographic challenge. The result was four carefully-considered choices of number sets, including Tech, which had no diagonal strokes. If letters are his friends, then numbers are difficult, beautiful women that flirt a lot but rarely behave. Spiekermann shared the challenges and history of number design, in person, on April 23, 2008:

"Anybody can design letters, but numbers are hard. Tech was an interesting challenge that I gave myself: to create a typeface that has no diagonals. When you design numbers, you have to do ABC at least. It’s interesting because I realized that what worked for the house numbers obviously doesn’t work for letters. This was going backwards. But numbers and letters are very different; they have different space, different shapes; they come from different places. Figures are actually my favorite part of type design.