I have a great supply of scrap wood in our garage and when I saw this piece I knew exactly what I wanted to make with it.
I started by marking every 5cm with a line; small line for 5cm and big for 10cm.
I then drew over with a thick permanent black marker.
I knew that free-handing the number would be risky so I printed out number in a font I liked, cut them out and stuck them on next to the correct line. I then traced the number with a pen, pushing just hard enough that the outline would show up on the wood.
I then traced the outline and filled it in.
I love the finished product and it suits the room perfectly.