diff --git a/src/aphorisms/twenty-one.clj b/src/aphorisms/twenty-one.clj
new file mode 100644
index 0000000..769c650
--- /dev/null
+++ b/src/aphorisms/twenty-one.clj
@@ -0,0 +1,61 @@
+(ns aphorisms.twenty-one
+  (:require [quil.core :as q]
+            [quil.middleware :as qm]
+            [thi.ng.geom.rect :as r]
+            [thi.ng.geom.core :as g]
+            [thi.ng.math.core :as m]))
+
+;; https://10print.org/
+
+(def bounds (r/rect 500 500))
+
+(defn setup []
+  (q/frame-rate 30)
+  (q/rect-mode :center)
+  (q/ellipse-mode :center)
+  (q/color-mode :hsb 360 100 100)
+  {})
+
+(defn update-state [state]
+  state)
+
+(def canvas
+  (as-> (g/scale bounds 0.92) b
+    (g/translate b (m/* (m/- (:size bounds) (:size b)) 0.5))))
+
+(def tile-size 10)
+
+(defn draw-tile [[x y] tile-type]
+  (let [start (case tile-type
+                :a 0
+                :b q/HALF-PI)]
+    (q/arc x y tile-size tile-size start (+ start q/PI))))
+
+(defn pick-at [xs rand-val]
+  (nth xs (Math/round (* rand-val (dec (count xs))))))
+
+(defn draw-state [_]
+  (q/background 200 10 100)
+  (q/no-fill)
+  (q/stroke-weight 1)
+  (q/stroke-cap :square)
+  (q/stroke 10 60 100)
+  (doseq [y (range (-> canvas :p :y) (+ (-> canvas :p :y) (-> canvas :size :y) tile-size) tile-size)
+          x (range (-> canvas :p :x) (+ (-> canvas :p :x) (-> canvas :size :x) tile-size) tile-size)
+          :let [n (q/noise (* 0.0000022 x (q/millis))
+                           (* 0.0000033 y (q/millis)))]]
+    (draw-tile [x y] (pick-at [:a :b] n))))
+
+(g/scale bounds 0.92)
+
+(g/scale (:size bounds) 0.92)
+
+#_:clj-kondo/ignore
+(q/defsketch twenty-one
+  :title "Twenty-One"
+  :size (:size bounds)
+  :Settings #(q/pixel-density (q/display-density))
+  :setup setup
+  :update update-state
+  :draw draw-state
+  :middleware [qm/pause-on-error qm/fun-mode])