Here is a height chart I made for my son:
This is made from solid Walnut. The numbers are simply house numbers. The tick marks taped out and painted in, then finished off with 5 coats of water-based polyurethane. To add in so extra ‘luster’, the finished surface is coated with Howard “Feed-N-Wax Wood Polish and Conditioner”.
In order to mark out my little boys height , we clean away the wax with rubbing alcohol, mark out his height with a white paint pen, and reapply a light coat of Feed-N-Wax to the area. So far so good.