PT20	Scale	Height	Spread
1500	1:1500	30	4
1000	1:1000	45	6
750	1:750	60	8
500	1:500	70	10
400	1:400	90	13
300	1:300	100	18
200	1:200	120	28
150	1:150	150	28
100	1:100	170	40
075	1:75	280	60