void setup() {
  size(100, 100);
  noLoop();
  smooth();
}

void draw() {
  for (int i = 0; i < 70; i++) { // Draw 70 X shapes
    drawX(int(random(255)), int(random(30)),
          int(random(width)), int(random(height)), 100);
  }
}

void drawX(int gray, int weight, int x, int y, int size) {
  stroke(gray);
  strokeWeight(weight);
  line(x, y, x+size, y+size);
  line(x+size, y, x, y+size);
}