Karel Martens: Perpetual Birthday Calendar

Karel Martens conceived this A3 wall calendar as a prototype in 1968. The design has been unrealized until now — a limited edition publication from Roma Publications. The Perpetual Birthday Calendar is built on a single die-cut shape, repeated across colored card stock, layered until the pattern multiplies into something that couldn't have been predicted from the piece alone. Thirteen sheets, each a different color, each punched to the same geometry. What changes is what's underneath.

Perpetual because it isn't year-specific — designed to track birthdays, anniversaries, or any date worth remembering across years.

Karel Martens for Roma Publications. Made in the Netherlands.

14 pages · 11.75 × 16.5 in. · softcover · spiral bound with hanging loop