Canvas.setpenopacity(1);

const spacing = 3;
const tilt = 20;     // min=-80 max=80 step=1
const wave = 30;      // min=0 max=80 step=1
const squeeze = 100;  // min=10 max=100 step=1

const turtle = new Turtle();

const factor = 50 / squeeze;

for (let y = -500; y <= 500; y += spacing) {

    const x1 = -80;
    const x2 = 80;

    const shift = Math.sin(y * 0.08) * wave;

    const y1 = y * factor;
    const y2 = (y + tilt) * factor;

    turtle.penup();
    turtle.goto(x1 + shift, y1);

    turtle.pendown();
    turtle.goto(x2 - shift, y2);
}